Method and apparatus for triggering aperiodic feedback in coordinated multipoint transmission

ABSTRACT

Embodiments of the present invention provide a method and apparatus for triggering aperiodic feedback in coordinated multipoint transmission. The method includes: transmitting, by an eNB to UE, dynamic control information (DCI) and preconfigured feedback sets corresponding to the DCI, so that the UE aperiodically feeds back corresponding channel state information (CSI) according to the DCI and the feedback sets corresponding to the DCI; wherein the preconfigured feedback sets corresponding to the DCI are classified according to a triggered transmitting point or a CSI-RS of non-zero power, or are classified according to configured CSI, or are classified according to an interference type. With the method and apparatus of the embodiments of the present invention, a relatively good tradeoff between flexibility of aperiodic CSI feedback and signaling load in a CoMP transmission process or a joint transmission process of CoMP and CA may be achieved.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/573,479, filed on Dec. 17, 2014 which is a continuation ofInternational Application No. PCT/CN2012/077115, filed on Jun. 18, 2012,now pending, the contents of which are herein wholly incorporated byreference.

TECHNICAL FIELD

The present invention relates to transmission technologies in acommunication system, and in particular to a method and apparatus fortriggering aperiodic feedback supporting coordinated multipointtransmission in an LTE-A system.

BACKGROUND

In an LTE-A (long-term evolution-advanced) system, coordinatedmultipoint (CoMP) transmission technologies are introduced to enhanceperformance of a cell-edge user as well as increase an averagethroughput of the cell. The following three schemes are standardized ina downlink CoMP technologies of LTE-A R11: joint transmission (JT),dynamic point selection and coordinated scheduling/beamforming. In orderthat link adaptive transmission is performed accurately and a gain ofCoMP transmission is obtained effectively, user equipment (UE) needs tofeed back accurate PMI (precoding matrix indicator)/CQI (channel qualityindication)/RI (rank indication) information for various transmissionassumptions. A feedback scheme where each CSI-RS (channel stateindication-RS) resource is at least supported was decided in the 3GPPRAN1 67 conference. And it was decided in the 3GPP RAN1 68 conferencethat a CoMP measurement set supports at most three CSI-RS resources. Asa mobile station is limited with respect to an actual processingability, a concrete number of reported CSI will be further limited.Actually, there exists a tradeoff between feedback overhead and systemperformance gain. Relatively more feedback information is advantageousto the system in acquiring a gain of the CoMP transmission; on the otherhand, it increases overhead of uplink feedback.

In an LTE Rel. 10 system, periodic and aperiodic feedback manners areused to provide an eNB with feedback information of differentgranularities, so as to improve performance of the system. Aperiodicfeedback has advantages of high capacity of feedback and low time delay,and fits feedback demand of CoMP. Hence, an effective triggeringmechanism is needed to be designed to support aperiodic feedback in CoMPtransmission.

Currently, aperiodic feedback is triggered via DCI (dynamic controlinformation). When a user is not configured with multicarriertransmission, a 1-bit CSI request domain in DCI format 0 or DCI format 4is employed to trigger aperiodic report of a corresponding mode; andwhen the user is configured with multicarrier transmission, a 2-bit CSIrequest domain in DCI format 0 or DCI format 4 is employed to triggeraperiodic report of a corresponding mode. As shown in Table 1, 00denotes that report is not triggered, 01 denotes aperiodic report of aprimary carrier is triggered, and 10 and 11 denote report of a set 1 anda set 2 configured by a high layer is triggered. Wherein, the set 1 andset 2 are configured via high-layer signaling, the high-layer signalingindicating via 8-bit bitmap information which of 8 subcarriers need tobe reported. At present, as at most 5 subcarriers are supported in anLTE-A system, at most 5 bits are actually configured as 1; that is,subcarriers to which bits configured as 1 correspond need to bereported. Furthermore, when aperiodic report is triggered in a commonsearch space, in order to meet length demand of DCI, triggering of 1-bitsignaling is only supported. When the user is configured withmulticarrier transmission, in consideration that carrier reconfigurationis an important scenario for transmitting DCI in a common search space,when 1-bit triggering signaling is configured as 1, only CSI of adownlink carrier (which is defined in a system information block 2)corresponding to triggering an uplink aperiodic feedback carrier is fedback.

TABLE 1 Interpretation of meanings of CSI domains Values of CSI requestdomains Explanations ‘00’ Aperiodic CSI report is not triggered ‘01’Aperiodic CSI report of a serving cell c is triggered ‘10’ Aperiodic CSIreport of a set 1 of a serving cell configured by a high layer istriggered ‘11’ Aperiodic CSI report of a set 2 of the serving cellconfigured by a high layer is triggered

It was found by the inventors in the implementation of the presentinvention that CSI fed back by a user includes rank indication (RI),precoding matrix indicator (PMI) and channel quality indication (CQI)information. An eNB configures each piece of CSI with CSI-RS resource ofnon-zero power and a measurement resource of interference part, and theuser uses these resources to measure and report the CSI. In CoMPtransmission, as multiple pieces of CSI (corresponding to differenttransmitting points and interference assumptions) need to be reported,feedback overhead is very large.

It should be noted that the above description of the background art ismerely provided for clear and complete explanation of the presentinvention and for easy understanding by those skilled in the art. And itshould not be understood that the above technical solution is known tothose skilled in the art as it is described in the background art of thepresent invention.

SUMMARY

An object of the embodiments of the present invention is to provide amethod and apparatus for triggering aperiodic feedback in coordinatedmultipoint transmission, so as to solve the problem that overhead ofdynamic signaling of the system is too large due to flexible CSIfeedback in a CoMP transmission process or a joint transmission processof CoMP and CA.

According to an aspect of the embodiments of the present invention,there is provided a method for triggering aperiodic feedback incoordinated multipoint transmission, including:

transmitting, by an eNB to UE, dynamic control information (DCI) andpreconfigured feedback sets corresponding to the DCI, so that the UEaperiodically feeds back corresponding channel state information (CSI)according to the DCI and the feedback sets corresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI, or areclassified according to an interference type.

According to another aspect of the embodiments of the present invention,there is provided a method for triggering aperiodic feedback incoordinated multipoint transmission, including:

receiving, by UE, DCI and preconfigured feedback sets corresponding tothe DCI transmitted by an eNB; and

feeding back aperiodically corresponding CSI by the UE according to theDCI and the feedback sets corresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI, or areclassified according to an interference type.

According to still another aspect of the embodiments of the presentinvention, there is provided a method for triggering aperiodic feedbackin coordinated multipoint transmission, including:

transmitting, by an eNB to UE, first DCI and preconfigured feedback setscorresponding to the first DCI, so that the UE aperiodically feeds backCSI of corresponding carrier aggregation (CA) according to the first DCIand the feedback sets corresponding to the first DCI; and

transmitting, by the eNB to the UE, second DCI and preconfiguredfeedback sets corresponding to the second DCI, so that the UEaperiodically feeds back CSI of corresponding coordinated multipointtransmission (CoMP) according to the second DCI and the feedback setscorresponding to the second DCI;

wherein the preconfigured feedback sets corresponding to the second DCIare classified according to a triggered transmitting point or a CSI-RSof non-zero power, or are classified according to configured CSI, or areclassified according to an interference type.

According to still another aspect of the embodiments of the presentinvention, there is provided a method for triggering aperiodic feedbackin coordinated multipoint transmission, including:

receiving, by UE, first DCI and preconfigured feedback setscorresponding to the first DCI transmitted by an eNB;

feeding back aperiodically CSI of corresponding CA by the UE accordingto the first DCI and the feedback sets corresponding to the first DCI;

receiving, by the UE, second DCI and preconfigured feedback setscorresponding to the second DCI transmitted by the eNB; and

feeding back aperiodically CSI of corresponding CoMP by the UE accordingto the second DCI and the feedback sets corresponding to the second DCI;

wherein the preconfigured feedback sets corresponding to the second DCIare classified according to a triggered transmitting point or a CSI-RSof non-zero power, or are classified according to configured CSI, or areclassified according to an interference type.

According to still another aspect of the embodiments of the presentinvention, there is provided a method for triggering aperiodic feedbackin coordinated multipoint transmission, including:

transmitting, by an eNB to UE, DCI and preconfigured feedback setscorresponding to the DCI, so that the UE aperiodically feeds back CSI ofcorresponding CA and CoMP according to the DCI and the feedback setscorresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI;

and wherein the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit corresponding to each triggered transmitting point oreach piece of configured CSI.

According to still another aspect of the embodiments of the presentinvention, there is provided a method for triggering aperiodic feedbackin coordinated multipoint transmission, including:

receiving, by UE, DCI and preconfigured feedback sets corresponding tothe DCI transmitted by an eNB; and

feeding back aperiodically CSI of corresponding CA and CoMP by the UEaccording to the DCI and the feedback sets corresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI;

and wherein the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit corresponding to each triggered transmitting point oreach piece of configured CSI.

According to still another aspect of the embodiments of the presentinvention, there is provided a method for triggering aperiodic feedbackin coordinated multipoint transmission, including:

transmitting, by an eNB to UE, DCI and preconfigured feedback setscorresponding to the DCI, so that the UE aperiodically feeds back CSI ofcorresponding CA and CoMP according to the DCI and the feedback setscorresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point (TP) or a CSI-RSof non-zero power, or are classified according to configured CSI;

and wherein the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating configured or activated carriers, and a TPindication bit for indicating a triggered TP corresponding to eachconfigured or activated carrier or a CSI indication bit for indicatingconfigured CSI corresponding to each configured or activated carrier, orthe RRC signaling including a carrier indication bit for indicatingconfigured or activated carriers, and a carrier indication bit forindicating a carrier corresponding to each triggered TP or correspondingto each piece of configured CSI.

According to still another aspect of the embodiments of the presentinvention, there is provided a method for triggering aperiodic feedbackin coordinated multipoint transmission, including:

receiving, by UE, DCI and preconfigured feedback sets corresponding tothe DCI transmitted by an eNB; and

feeding back aperiodically CSI of corresponding CA and CoMP by the UEaccording to the DCI and the feedback sets corresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI;

and wherein the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating configured or activated carriers, and a TPindication bit for indicating a triggered TP corresponding to eachconfigured or activated carrier or a CSI indication bit for indicatingconfigured CSI corresponding to each configured or activated carrier, orthe RRC signaling including a carrier indication bit for indicatingconfigured or activated carriers, and a carrier indication bit forindicating carrier corresponding to each triggered TP or each piece ofconfigured CSI.

According to still another aspect of the embodiments of the presentinvention, there is provided a method for triggering aperiodic feedbackin coordinated multipoint transmission, including:

transmitting, by an eNB to UE, DCI and preconfigured feedback setscorresponding to the DCI, so that the UE aperiodically feeds back CSI ofcorresponding CA and CoMP according to the DCI and the feedback setscorresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI;

and wherein the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating triggered aperiodically fed back carriers,and a TP indication bit for indicating a triggered TP corresponding toeach triggered carrier or a CSI indication bit for indicating configuredCSI corresponding to each triggered carrier, or the RRC signalingincluding a carrier indication bit for indicating triggeredaperiodically fed back carriers, and a carrier indication bit forindicating a carrier corresponding to each triggered TP or correspondingto each piece of configured CSI.

According to still another aspect of the embodiments of the presentinvention, there is provided a method for triggering aperiodic feedbackin coordinated multipoint transmission, including:

receiving, by UE, DCI and preconfigured feedback sets corresponding tothe DCI transmitted by an eNB; and

feeding back aperiodically CSI of corresponding CA and CoMP by the UEaccording to the DCI and the feedback sets corresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI;

and wherein the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating triggered aperiodically fed back carriers,and a TP indication bit for indicating a triggered TP corresponding to atriggered carrier or a CSI indication bit for indicating configured CSIcorresponding to a triggered carrier, or the RRC signaling including acarrier indication bit for indicating triggered aperiodically fed backcarriers, and a carrier indication bit for indicating a carriercorresponding to each triggered TP or configured CSI.

According to still another aspect of the embodiments of the presentinvention, there is provided a method for triggering aperiodic feedbackin coordinated multipoint transmission, including:

transmitting, by an eNB to UE, DCI and preconfigured feedback setscorresponding to the DCI, so that the UE aperiodically feeds back CSI ofcorresponding CA and CoMP according to the DCI and the feedback setscorresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI;

and wherein the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating triggered carriers, and a TP indicationbit or a CSI indication bit for indicating fed back contentscorresponding to all triggered carriers.

According to still another aspect of the embodiments of the presentinvention, there is provided a method for triggering aperiodic feedbackin coordinated multipoint transmission, including:

receiving, by UE, DCI and preconfigured feedback sets corresponding tothe DCI transmitted by an eNB; and

feeding back aperiodically CSI of corresponding CA and CoMP by the UEaccording to the DCI and the feedback sets corresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI;

and wherein the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating triggered carriers, and a TP indicationbit or a CSI indication bit for indicating fed back contentscorresponding to all triggered carriers.

According to still another aspect of the embodiments of the presentinvention, there is provided a method for triggering aperiodic feedbackin coordinated multipoint transmission, including:

transmitting DCI by an eNB to UE, so that the UE aperiodically feedsback corresponding CSI according to the DCI and preconfigured feedbackcommitted information corresponding to the DCI;

wherein the preconfigured feedback committed information correspondingto the DCI is feeding back all the CSI of a first CSI-RS resource ofnon-zero power, or feeding back first CSI in an aperiodic feedback CSIset, or feeding back first CSI in a triggered aperiodic feedback CSIset.

According to still another aspect of the embodiments of the presentinvention, there is provided a method for triggering aperiodic feedbackin coordinated multipoint transmission, including:

receiving, by UE, DCI transmitted by an eNB; and

feeding back aperiodically corresponding CSI by the UE according to theDCI and preconfigured feedback committed information corresponding tothe DCI;

wherein the preconfigured feedback committed information correspondingto the DCI is feeding back all the CSI of a first CSI-RS resource ofnon-zero power, or feeding back first CSI in an aperiodic feedback CSIset, or feeding back first CSI in a triggered aperiodic feedback CSIset.

According to still another aspect of the embodiments of the presentinvention, there is provided a method for triggering aperiodic feedbackin coordinated multipoint transmission, including:

transmitting, by an eNB to UE, DCI and a preconfigured anchor CSIresource, so that the UE aperiodically feeds back corresponding CSIaccording to the DCI and the anchor CSI;

wherein the anchor CSI resource is at least one CSI resource to which aCSI-RS of non-zero power corresponds, or at least one CSI resource in anaperiodic feedback CSI set;

and wherein the preconfigured anchor CSI resource is indicated via RRCsignaling, the RRC signaling including log₂(N) bits, N bits, log₂(M)bits, or M bits, for indicating the anchor CSI resource; where N is thesize of a measurement set of CoMP, and M is the size of a CSI setconfigured by the eNB for aperiodic feedback; wherein when the RRCsignaling indicates the anchor CSI resource via N bits or M bits, theindication is performed in a manner of a bitmap.

According to still another aspect of the embodiments of the presentinvention, there is provided a method for triggering aperiodic feedbackin coordinated multipoint transmission, including:

receiving, by UE, DCI and a preconfigured anchor CSI resourcetransmitted by an eNB; and

feeding back aperiodically corresponding CSI by the UE according to theDCI and the anchor CSI resource;

wherein the anchor CSI resource is at least one CSI resource to which aCSI-RS of non-zero power corresponds, or at least one CSI resource in anaperiodic feedback CSI set;

and wherein the preconfigured anchor CSI resource is indicated via RRCsignaling, the RRC signaling including log₂(N) bits, N bits, log₂(M)bits, or M bits, for indicating the anchor CSI resource; where N is thesize of a measurement set of CoMP, and M is the size of a CSI setconfigured by the eNB for aperiodic feedback; wherein when the RRCsignaling indicates the anchor CSI resource via N bits or M bits, theindication is performed in a manner of a bitmap.

According to still another aspect of the embodiments of the presentinvention, there is provided an eNB, configured to trigger UE toaperiodically feed back CSI, the eNB including:

a transmitting unit configured to transmit to UE, 1-bit or 2-bit DCI andfeedback sets corresponding to the DCI preconfigured via RRC signaling,so that the UE aperiodically feeds back corresponding CSI according tothe DCI and the feedback sets corresponding to the DCI;

wherein the feedback sets corresponding to the DCI preconfigured via RRCsignaling are classified according to a triggered transmitting point ora CSI-RS of non-zero power, or are classified according to configuredCSI, or are classified according to an interference type;

and wherein the number of the feedback sets corresponding to the 1-bitDCI is 1, and the number of the feedback sets corresponding to the 2-bitDCI is 3 or 2.

According to still another aspect of the embodiments of the presentinvention, there is provided UE, including:

a receiving unit configured to receive 1-bit or 2-bit DCI and feedbacksets corresponding to the DCI preconfigured via RRC signalingtransmitted by an eNB; and

a reporting unit configured to feed back aperiodically corresponding CSIaccording to the DCI and the feedback sets corresponding to the DCI;

wherein the feedback sets corresponding to the DCI preconfigured via RRCsignaling are classified according to a triggered transmitting point ora CSI-RS of non-zero power, or are classified according to configuredCSI, or are classified according to an interference type;

and wherein the number of the feedback sets corresponding to the 1-bitDCI is 1, and the number of the feedback sets corresponding to the 2-bitDCI is 3 or 2.

According to still another aspect of the embodiments of the presentinvention, there is provided an eNB, configured to trigger UE toaperiodically feed back CSI, the eNB including:

a first transmitting unit configured to transmit to the UE, 1-bit or2-bit first DCI and feedback sets corresponding to the first DCIpreconfigured via RRC signaling, so that the UE aperiodically feeds backCSI of corresponding CA according to the first DCI and the feedback setscorresponding to the first DCI; and

a second transmitting unit configured to transmit to the UE, 1-bit or2-bit second DCI and feedback sets corresponding to the second DCIpreconfigured via RRC signaling, so that the UE aperiodically feeds backCSI of corresponding CoMP according to the second DCI and the feedbacksets corresponding to the second DCI;

wherein the feedback sets corresponding to the DCI preconfigured via RRCsignaling are classified according to a triggered transmitting point ora CSI-RS of non-zero power, or are classified according to configuredCSI, or are classified according to an interference type;

and wherein the number of the feedback sets corresponding to the 1-bitfirst DCI is 1, the number of the feedback sets corresponding to the1-bit second DCI is 1, the number of the feedback sets corresponding tothe 2-bit first DCI is 3 or 2, and the number of the feedback setscorresponding to the 2-bit second DCI is 3 or 2.

According to still another aspect of the embodiments of the presentinvention, there is provided UE, including:

a first receiving unit configured to receive 1-bit or 2-bit first DCIand feedback sets corresponding to the first DCI preconfigured via RRCsignaling transmitted by an eNB;

a first reporting unit configured to feed back aperiodically CSI ofcorresponding CA according to the first DCI and the feedback setscorresponding to the first DCI;

a second receiving unit configured to receive 1-bit or 2-bit second DCIand preconfigured feedback sets corresponding to the second DCItransmitted by the eNB; and

a second reporting unit configured to feed back aperiodically CSI ofcorresponding CoMP according to the second DCI and the feedback setscorresponding to the second DCI;

wherein the preconfigured feedback sets corresponding to the second DCIare classified according to a triggered transmitting point or a CSI-RSof non-zero power, or are classified according to configured CSI, or areclassified according to an interference type;

and wherein the number of the feedback sets corresponding to the 1-bitfirst DCI is 1, the number of the feedback sets corresponding to the1-bit second DCI is 1, the number of the feedback sets corresponding tothe 2-bit first DCI is 3 or 2, and the number of the feedback setscorresponding to the 2-bit second DCI is 3 or 2.

According to still another aspect of the embodiments of the presentinvention, there is provided an eNB, configured to trigger UE toaperiodically feed back CSI, the eNB including:

a transmitting unit configured to transmit to the UE, 2-bit DCI andfeedback sets corresponding to the DCI preconfigured via RRC signaling,so that the UE aperiodically feeds back CSI of corresponding CA and CoMPaccording to the DCI and the feedback sets corresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI;

wherein the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit corresponding to each triggered transmitting point oreach piece of configured CSI;

and wherein the number of the feedback sets corresponding to the 2-bitDCI is 3 or 2.

According to still another aspect of the embodiments of the presentinvention, there is provided UE, including:

a receiving unit configured to receive 2-bit DCI and feedback setscorresponding to the DCI preconfigured via RRC signaling transmitted byan eNB; and

a reporting unit configured to feed back aperiodically CSI ofcorresponding CA and CoMP according to the DCI and the feedback setscorresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI;

wherein the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit corresponding to each triggered transmitting point oreach piece of configured CSI;

and wherein the number of the feedback sets corresponding to the 2-bitDCI is 3 or 2.

According to still another aspect of the embodiments of the presentinvention, there is provided an eNB, configured to trigger UE toaperiodically feed back CSI, the eNB including:

a transmitting unit configured to transmit to the UE, 2-bit DCI andfeedback sets corresponding to the DCI preconfigured via RRC signaling,so that the UE aperiodically feeds back CSI of corresponding CA and CoMPaccording to the DCI and the feedback sets corresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI;

wherein the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating configured or activated carriers, and a TPindication bit for indicating a triggered TP corresponding to eachconfigured or activated carrier or a CSI indication bit for indicatingconfigured CSI corresponding to each configured or activated carrier, orthe RRC signaling including a carrier indication bit for indicatingconfigured or activated carriers, and a carrier indication bit forindicating a carrier corresponding to each triggered TP or correspondingto each piece of configured CSI;

and wherein the number of the feedback sets corresponding to the 2-bitDCI is 3 or 2.

According to still another aspect of the embodiments of the presentinvention, there is provided UE, including:

a receiving unit configured to receive 2-bit DCI and feedback setscorresponding to the DCI preconfigured via RRC signaling transmitted byan eNB; and

a reporting unit configured to feed back aperiodically CSI ofcorresponding CA and CoMP according to the DCI and the feedback setscorresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI;

wherein the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating configured or activated carriers, and a TPindication bit for indicating a triggered TP corresponding to eachconfigured or activated carrier or a CSI indication bit for indicatingconfigured CSI corresponding to each configured or activated carrier, orthe RRC signaling including a carrier indication bit for indicatingconfigured or activated carriers, and a carrier indication bit forindicating a carrier corresponding to each triggered TP or configuredCSI;

and wherein the number of the feedback sets corresponding to the 2-bitDCI is 3 or 2.

According to still another aspect of the embodiments of the presentinvention, there is provided an eNB, configured to trigger UE toaperiodically feed back CSI, the eNB including:

a transmitting unit configured to transmit to the UE, 2-bit DCI andfeedback sets corresponding to the DCI preconfigured via RRC signaling,so that the UE aperiodically feeds back CSI of corresponding CA and CoMPaccording to the DCI and the feedback sets corresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI;

wherein the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating triggered aperiodically fed back carriers,and a TP indication bit for indicating a triggered TP corresponding toeach triggered carrier or a CSI indication bit for indicating configuredCSI corresponding to each triggered carrier, or the RRC signalingincluding a carrier indication bit for indicating triggeredaperiodically fed back carriers, and a carrier indication bit forindicating a carrier corresponding to each triggered TP or correspondingto each piece of configured CSI;

and wherein the number of the feedback sets corresponding to the 2-bitDCI is 3 or 2.

According to still another aspect of the embodiments of the presentinvention, there is provided UE, including:

a receiving unit configured to receive 2-bit DCI and feedback setscorresponding to the DCI preconfigured via RRC signaling transmitted byan eNB; and

a reporting unit configured to feed back aperiodically CSI ofcorresponding CA and CoMP according to the DCI and the feedback setscorresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI;

wherein the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating triggered aperiodically fed back carriers,and a TP indication bit for indicating a triggered TP corresponding to atriggered carrier or a CSI indication bit for indicating configured CSIcorresponding to a triggered carrier, or the RRC signaling including acarrier indication bit for indicating triggered aperiodically fed backcarriers, and a carrier indication bit for indicating a carriercorresponding to each triggered TP or configured CSI;

and wherein the number of the feedback sets corresponding to the 2-bitDCI is 3 or 2.

According to still another aspect of the embodiments of the presentinvention, there is provided an eNB, configured to trigger UE toaperiodically feed back CSI, the eNB including:

a transmitting unit configured to transmit to the UE, 2-bit DCI andfeedback sets corresponding to the DCI preconfigured via RRC signaling,so that the UE aperiodically feeds back CSI of corresponding CA and CoMPaccording to the DCI and the feedback sets corresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI;

wherein the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating triggered carriers, and a TP indicationbit or a CSI indication bit for indicating fed back contentscorresponding to all triggered carriers;

and wherein the number of the feedback sets corresponding to the 2-bitDCI is 3 or 2.

According to still another aspect of the embodiments of the presentinvention, there is provided UE, including:

a receiving unit configured to receive 2-bit DCI and feedback setscorresponding to the DCI preconfigured via RRC signaling transmitted byan eNB; and

a reporting unit configured to feed back aperiodically CSI ofcorresponding CA and CoMP according to the DCI and the feedback setscorresponding to the DCI;

wherein the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI;

wherein the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating triggered carriers, and a TP indicationbit or a CSI indication bit for indicating fed back contentscorresponding to all triggered carriers;

and wherein the number of the feedback sets corresponding to the 2-bitDCI is 3 or 2.

According to still another aspect of the embodiments of the presentinvention, there is provided an eNB, configured to trigger UE toaperiodically feed back CSI, the eNB including:

a transmitting unit configured to transmit 1-bit DCI to the UE, so thatthe UE aperiodically feeds back corresponding CSI according to the DCIand preconfigured feedback committed information corresponding to theDCI;

wherein the preconfigured feedback committed information correspondingto the DCI is feeding back all the CSI of a first CSI-RS resource ofnon-zero power, or feeding back first CSI in an aperiodic feedback CSIset, or feeding back first CSI in a triggered aperiodic feedback CSIset.

According to still another aspect of the embodiments of the presentinvention, there is provided UE, including:

a receiving unit configured to receive 1-bit DCI transmitted by an eNB;and

a reporting unit configured to feed back aperiodically corresponding CSIaccording to the DCI and preconfigured feedback committed informationcorresponding to the DCI;

wherein the preconfigured feedback committed information correspondingto the DCI is feeding back all the CSI of a first CSI-RS resource ofnon-zero power, or feeding back first CSI in an aperiodic feedback CSIset, or feeding back first CSI in a triggered aperiodic feedback CSIset.

According to still another aspect of the embodiments of the presentinvention, there is provided an eNB, configured to trigger UE toaperiodically feed back CSI, the eNB including:

a transmitting unit configured to transmit to the UE, 1-bit DCI and ananchor CSI resource preconfigured via RRC signaling, so that the UEaperiodically feeds back corresponding CSI according to the DCI and theanchor CSI;

wherein the preconfigured anchor CSI resource is at least one CSIresource to which a CSI-RS of non-zero power corresponds, or at leastone CSI resource in an aperiodic feedback CSI set;

and wherein the preconfigured anchor CSI resource is indicated via RRCsignaling, the RRC signaling including log₂(N) bits, N bits, log₂(M)bits, or M bits, for indicating the anchor CSI resource; where N is thesize of a measurement set of CoMP, and M is the size of a CSI setconfigured by the eNB for aperiodic feedback; wherein when the RRCsignaling indicates the anchor CSI resource via N bits or M bits, theindication is performed in a manner of a bitmap.

According to still another aspect of the embodiments of the presentinvention, there is provided UE, including:

a receiving unit configured to receive 1-bit DCI and an anchor CSIresource preconfigured via high-layer signaling transmitted by an eNB;and

a reporting unit configured to feed back aperiodically corresponding CSIaccording to the DCI and the anchor CSI resource;

wherein the preconfigured anchor CSI resource is at least one CSIresource to which a CSI-RS of non-zero power corresponds, or at leastone CSI resource in an aperiodic feedback CSI set;

and wherein the preconfigured anchor CSI resource is indicated via RRCsignaling, the RRC signaling including log₂(N) bits, N bits, log₂(M)bits, or M bits, for indicating the anchor CSI resource; where N is thesize of a measurement set of CoMP, and M is the size of a CSI setconfigured by the eNB for aperiodic feedback; wherein when the RRCsignaling indicates the anchor CSI resource via N bits or M bits, theindication is performed in a manner of a bitmap.

According to still another aspect of the embodiments of the presentinvention, there is provided a computer-readable program, wherein whenthe program is executed in an eNB, the program enables a computer tocarry out the method for triggering aperiodic feedback in coordinatedmultipoint transmission as described above in the eNB.

According to still another aspect of the embodiments of the presentinvention, there is provided a storage medium in which acomputer-readable program is stored, wherein the computer-readableprogram enables a computer to carry out the method for triggeringaperiodic feedback in coordinated multipoint transmission as describedabove in an eNB.

According to still another aspect of the embodiments of the presentinvention, there is provided a computer-readable program, wherein whenthe program is executed in terminal equipment, the program enables acomputer to carry out the method for triggering aperiodic feedback incoordinated multipoint transmission as described above in the terminalequipment.

According to still another aspect of the embodiments of the presentinvention, there is provided a storage medium in which acomputer-readable program is stored, wherein the computer-readableprogram enables a computer to carry out the method for triggeringaperiodic feedback in coordinated multipoint transmission as describedabove in terminal equipment.

An advantage of the embodiments of the present invention exists in thatwith the method and apparatus for triggering aperiodic feedback proposedby the embodiments of the present invention, different triggeredcontents are proposed, and the triggering manner taking CSI as triggeredcontents is good in flexibility. Different signaling designs are givenin detail for different triggered contents. Taking joint transmission ofCoMP and CA into account, joint methods for indicating triggeringinformation are proposed. RRC signaling overhead may further be loweredaccording to the number of carriers configured by the system for theuser. Taking characteristics of a common search space into account, twomethods for aperiodically triggering are proposed to effectively triggeraperiodic report.

With reference to the following description and drawings, the particularembodiments of the present invention are disclosed in detail, and theprinciple of the present invention and the manners of use are indicated.It should be understood that the scope of the embodiments of the presentinvention is not limited thereto. The embodiments of the presentinvention contain many alternations, modifications and equivalentswithin the spirits and scope of the terms of the appended claims.

Features that are described and/or illustrated with respect to oneembodiment may be used in the same way or in a similar way in one ormore other embodiments and/or in combination with or instead of thefeatures of the other embodiments.

It should be emphasized that the term “includes/including” when used inthis specification is taken to specify the presence of stated features,integers, steps or components but does not preclude the presence oraddition of one or more other features, integers, steps, components orgroups thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the invention can be better understood with reference tothe following drawings. The components in the drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the present invention. To facilitateillustrating and describing some parts of the invention, correspondingportions of the drawings may be exaggerated in size, e.g., made largerin relation to other parts than in an exemplary device actually madeaccording to the invention. Elements and features depicted in onedrawing or embodiment of the invention may be combined with elements andfeatures depicted in one or more additional drawings or embodiments.Moreover, in the drawings, like reference numerals designatecorresponding parts throughout the several views and may be used todesignate corresponding parts in more than one embodiments. In thedrawings:

FIG. 1 is a flowchart of a method for triggering aperiodic feedback incoordinated multipoint transmission in triggering aperiodic feedback ina user search space in a CoMP transmission scenario of Embodiment 1 ofthe present invention;

FIGS. 2a and 2b are schematic diagrams of the structure of RRC signalingin the method of Embodiment 1;

FIG. 3 is a flowchart of processing at a UE side of Embodiment 2 of thepresent invention corresponding to the method of Embodiment 1;

FIG. 4 is a flowchart of a method for triggering aperiodic feedback incoordinated multipoint transmission in triggering aperiodic feedback ina user search space in a joint transmission scenario of CoMP and CA ofEmbodiment 3 of the present invention;

FIG. 5 is a flowchart of processing at a UE side of Embodiment 4 of thepresent invention corresponding to the method of Embodiment 3;

FIG. 6 is a flowchart of a method for triggering aperiodic feedback incoordinated multipoint transmission in triggering aperiodic feedback ina user search space in a joint transmission scenario of CoMP and CA ofEmbodiment 5 of the present invention;

FIGS. 7a and 7b are schematic diagrams of the structure of RRC signalingaccording to the method of Embodiment 5;

FIG. 8 is a flowchart of processing at a UE side of Embodiment 6 of thepresent invention corresponding to the method of Embodiment 5;

FIG. 9 is a flowchart of a method for triggering aperiodic feedback incoordinated multipoint transmission in triggering aperiodic feedback ina user search space in a joint transmission scenario of CoMP and CA ofEmbodiment 7 of the present invention;

FIGS. 10a and 10b are schematic diagrams of the structure of RRCsignaling according to Embodiment 7;

FIG. 11 is a flowchart of processing at a UE side of Embodiment 8 of thepresent invention corresponding to the method of Embodiment 7;

FIG. 12 is a flowchart of a method for triggering aperiodic feedback incoordinated multipoint transmission in triggering aperiodic feedback ina user search space in a joint transmission scenario of CoMP and CA ofEmbodiment 9 of the present invention;

FIGS. 13a and 13b are schematic diagrams of the structure of RRCsignaling according to Embodiment 9;

FIG. 14 is a flowchart of processing at a UE side of Embodiment 10 ofthe present invention corresponding to the method of Embodiment 9;

FIG. 15 is a flowchart of a method for triggering aperiodic feedback incoordinated multipoint transmission in triggering aperiodic feedback ina user search space in a joint transmission scenario of CoMP and CA ofEmbodiment 11 of the present invention;

FIGS. 16a and 16b are schematic diagrams of the structure of RRCsignaling according to Embodiment 11;

FIG. 17 is a flowchart of processing at a UE side of Embodiment 12 ofthe present invention corresponding to the method of Embodiment 11;

FIG. 18 is a flowchart of a method for triggering aperiodic feedback incoordinated multipoint transmission in triggering aperiodic feedback ina common search space of Embodiment 13 of the present invention;

FIG. 19 is a flowchart of processing at a UE side of Embodiment 14 ofthe present invention corresponding to method of Embodiment 13;

FIG. 20 is a flowchart of a method for triggering aperiodic feedback incoordinated multipoint transmission in triggering aperiodic feedback ina common search space of Embodiment 15 of the present invention;

FIG. 21 is a flowchart of processing at a UE side of Embodiment 16 ofthe present invention corresponding to method of Embodiment 15;

FIG. 22 is a schematic diagram of the structure of an eNB an embodimentof the present invention corresponding to Embodiment 1;

FIG. 23 is a schematic diagram of the structure of UE an embodiment ofthe present invention corresponding to Embodiment 2;

FIG. 24 is a schematic diagram of the structure of an eNB an embodimentof the present invention corresponding to Embodiment 3;

FIG. 25 is a schematic diagram of the structure of UE an embodiment ofthe present invention corresponding to Embodiment 4;

FIG. 26 is a schematic diagram of the structure of an eNB an embodimentof the present invention corresponding to Embodiment 5;

FIG. 27 is a schematic diagram of the structure of UE an embodiment ofthe present invention corresponding to Embodiment 6;

FIG. 28 is a schematic diagram of the structure of an eNB an embodimentof the present invention corresponding to Embodiment 7;

FIG. 29 is a schematic diagram of the structure of UE an embodiment ofthe present invention corresponding to Embodiment 8;

FIG. 30 is a schematic diagram of the structure of an eNB an embodimentof the present invention corresponding to Embodiment 9;

FIG. 31 is a schematic diagram of the structure of UE an embodiment ofthe present invention corresponding to Embodiment 10;

FIG. 32 is a schematic diagram of the structure of an eNB an embodimentof the present invention corresponding to Embodiment 11;

FIG. 33 is a schematic diagram of the structure of UE an embodiment ofthe present invention corresponding to Embodiment 12;

FIG. 34 is a schematic diagram of the structure of an eNB an embodimentof the present invention corresponding to Embodiment 13;

FIG. 35 is a schematic diagram of the structure of UE an embodiment ofthe present invention corresponding to Embodiment 14;

FIG. 36 is a schematic diagram of the structure of an eNB an embodimentof the present invention corresponding to Embodiment 15; and

FIG. 37 is a schematic diagram of the structure of UE an embodiment ofthe present invention corresponding to Embodiment 16.

DETAILED DESCRIPTION

The foregoing and other features of the embodiments of the presentinvention shall become apparent with reference to the drawings and thefollowing description. These embodiments are illustrative only, and arenot intended to limit the present invention. For the principle andimplementation modes of the present invention to be easily understood bythose skilled in the art, the implementation modes of the presentinvention shall be described taking a method for triggering aperiodicfeedback in CoMP transmission in an LTE-A system as an example. However,it should be understood that the present invention is not limited to theabove system, and is applicable to other systems related to triggeringaperiodic feedback.

A method of combining DCI and high-layer signaling is followed in thefollowing embodiments, so as obtain a relatively good tradeoff betweenflexibility of triggering aperiodic feedback and an amount of signalingload. For the methods of the embodiments of the present invention to bemore clear and easy to be understood, the methods for triggeringaperiodic feedback of various embodiments of the present invention shallbe described below taking different application scenarios, such as ascenario of triggering in a user search space (a CoMP transmissionscenario, and a scenario of combining CoMP and CA), and a scenario oftriggering in a common search space (a CoMP transmission scenario, and ascenario of combining CoMP and CA), as examples. However, the methodsfor triggering aperiodic feedback in different scenarios are notindependent of each other. For example, the methods for triggering inthe CoMP transmission scenario may also be applicable to the scenario ofjoint transmission scenario of CoMP and CA, and the methods fortriggering in a user search space may also be applicable to the methodsof triggering in a common search space in the CoMP transmissionscenario, which shall be described below.

CoMP Scenario where Aperiodic Feedback is Triggered in a User SearchSpace

In an LTE-A system, in order to support the CoMP transmission, CSI atdifferent transmitting points and in different interference assumptionsneeds to be fed back. In order to obtain a tradeoff between feedbackflexibility and signaling overhead, a method of combining dynamic DCIand high-layer RRC signaling is used in the embodiments of the presentinvention.

Embodiment 1

An embodiment of the present invention provides a method for triggeringaperiodic feedback in coordinated multipoint transmission. FIG. 1 is aflowchart of the method. Referring to FIG. 1, the method includes:

step 101: transmitting, by an eNB to UE, dynamic control information(DCI) and preconfigured feedback sets corresponding to the DCI, so as totrigger the UE to aperiodically feed back corresponding channel stateinformation (CSI) according to the DCI and the feedback setscorresponding to the DCI.

In this embodiment, the aperiodic feedback is triggered in a user searchspace. Therefore, the DCI signaling may reuse 2-bit information in a CSIrequesting domain of DCI format0 or DCI format4. That is, when theaperiodic feedback (report) is triggered in the user search space, theeNB triggers the UE to perform the aperiodic feedback of the CSI bytransmitting 2-bit CSI requesting signaling (DCI) to the UE. In animplementation mode, for the 2-bit DCI, 00 indicates not triggeringaperiodic report, and 01, 10 and 11 indicate respectively triggeringaperiodic report of a feedback set 1, a feedback set 2 and a feedbackset 3, which are configured by a high layer. In another implementationmode, for the 2-bit DCI, 00 indicates not triggering aperiodic report,01 indicates triggering CSI report of an anchor cell (a primary cell ora specific single cell), and 10 and 11 indicate respectively triggeringaperiodic report of a feedback set 1 and a feedback set 2, which areconfigured by a high layer.

In this embodiment, corresponding to each non-all-zero bit, such as 01,10 and 11, of the DCI, the eNB preconfigures a corresponding feedbackset, that is, the above feedback set 1, feedback set 2 or feedback set3, so that the UE performs aperiodic feedback of the corresponding CSIaccording to a content indicated by a bit of the received DCI and acorresponding feedback set.

In this embodiment, if a periodically fed back CSI set is a subset of anaperiodically fed back CSI set, the eNB may realize indication ofperiodic and aperiodic CSI feedback by configuring directly a CSI setvia high-layer signaling (RRC signaling). Wherein, the aperiodic CSIfeedback use this set directly. And if an aperiodically fed back CSI setis unable to contain a periodically fed back CSI set, the eNB not onlyneeds to configure a CSI set needed by joint feedback via high-layersignaling, but also needs to configure a CSI set for the aperiodicfeedback via high-layer signaling. At this moment, the abovepreconfigured feedback sets corresponding to the DCI are selected fromthe CSI set configured for the aperiodic feedback by the high layer.

Wherein, the preconfigured feedback sets corresponding to the DCI may beclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or may be classified according to configured CSI, or maybe classified according to an interference type.

In an embodiment, the feedback sets are classified according to atriggered transmitting point (TP) or a CSI-RS of non-zero power, in thisembodiment, each feedback set is used to indicate a CSI set to which atransmitting point needing to be triggered or a CSI-RS of non-zero powercorresponds. For example, feedback sets 1, 2 and 3 denote CSI sets towhich triggered transmitting points or CSI-RSs of non-zero powercorrespond, respectively. In this embodiment, assuming that the size ofa CoMP measurement set is N, the feedback sets may be indicated bybitmaps of N bits of radio resource control (RRC) signaling. Wherein,the triggered transmitting points are configured as 1 in the bitmaps ofN bits. Taking N=3 as an example, that is, the size of the CoMPmeasurement set is 3, there may be 3 transmitting points for performingCoMP transmission. Assuming that two transmitting points are triggeredin the feedback set 1, in the bitmaps of 3 bits of the RRC signaling,the bits corresponding to the two transmitting points are configured as1, as shown in FIG. 2 a.

In this embodiment, as each CSI-RS of non-zero power may correspond todifferent interference assumptions, it will contain multiple pieces ofCSI. Hence, the feedback sets may be classified in this embodimentaccording to the CSI-RSs of non-zero power; that is, the feedback setsindicate to report all pieces of CSI containing CSI-RSs of non-zeropower in possible aperiodic feedback CSI sets.

In this embodiment, in order to increase flexibility, the eNB mayfurther preconfigure interference assumptions needing to be fed backcorresponding to each CSI-RS of non-zero power, so that the UEaperiodically feeds back corresponding CSI according to the interferenceassumptions. The interference assumptions may also be configured via RRCsignaling. Taking still that the size of a CoMP measurement set is N asan example, in this embodiment, the interference assumptions may beconfigured via RRC signaling of 2^((N-1)) bits; wherein, each bit beingconfigured as 1 shows that the CSI under a corresponding interferenceassumption needs to be fed back.

In another embodiment, the feedback sets are classified according to theconfigured CSI, in this embodiment, each feedback set is used toindicate a CSI set needing to be triggered. For example, feedback sets1, 2 and 3 respectively denote CSI sets needing to be triggered.

In this embodiment, the feedback sets may be indicated by bitmaps of Mbits of RRC signaling; where, M is the size of a CSI set configured bythe eNB for the aperiodic feedback, and may also be the largest size ofa CSI set of aperiodic report that can be supported by the user; forexample, M=5 or 6. Wherein, a bit configured as 1 denotes thatcorresponding CSI needs to be fed back, taking M=5 as an example, amanner of indication of the feedback sets is as shown in FIG. 2b . Withsuch a method of classification, granularities of indicating aperiodicfeedback are more fine.

In another embodiment, the feedback sets are classified according to aninterference type, in this embodiment, each feedback set is used toindicate a CSI set to which a possible interference type corresponds.For example, feedback sets 1, 2 and 3 respectively denote report ofpossible interference types.

In this embodiment, taking still that the size of a CoMP measurement setis N as an example, as there exist 2^((N-1)) possible interferencetypes, the feedback sets may be indicated via RRC signaling of 2^((N-1))bitmap bits, which denote interference types needing to be reported.That is, in a CSI set of aperiodic feedback, all the CSI containing theinterference types indicated by the feedback sets (CSI containingmultiple assumptions of CSI-RS of non-zero power) needs to be reported.For example, for a CoMP set with the size of a measurement set being 3,4 bits need to be employed respectively to indicate reported CSIinformation in sets 1, 2 and 3.

In the above embodiments, new RRC signaling may be employed to indicatea feedback set of dynamically triggered aperiodic feedback, such as theRRC signaling shown in FIGS. 2a and 2b ; and 8-bit RRC indicationsignaling in a carrier aggregation (CA) system may be reused to indicatea CSI feedback set of dynamically triggered aperiodic feedback. Thisembodiment is not limited thereto, and classifying the feedback setsaccording to the above-described method of classification andconfiguring corresponding number of bits of RRC signaling to indicatethe feedback sets according to the method of classification are allcovered by the protection scope of the present invention.

By using the method of this embodiment to trigger the UE to performaperiodic feedback, the UE selectively performs report according toconditions defined by the feedback sets, reports only a CSI set to whicha triggered transmitting point corresponds, reports only a CSI set towhich a CSI-RS of non-zero power corresponds, reports only a triggeredCSI set, or reports only CSI sets to which some interference typescorrespond, instead of reporting all the CSI (multiple pieces of CSIcorresponding to different transmitting points and interferenceassumption conditions), thereby solving the problem of large feedbackoverhead due to that the multiple pieces of CSI corresponding todifferent transmitting points and interference assumption conditionsneed to be reported, and realizing a relatively good tradeoff betweenfeedback flexibility and system signaling overhead.

Embodiment 2

An embodiment of the present invention further provides a method fortriggering aperiodic feedback in coordinated multipoint transmission,which is processing at a UE side corresponding to the method ofEmbodiment 1. FIG. 3 is a flowchart of the method. Referring to FIG. 3,the method includes:

step 301: receiving, by user equipment (UE), DCI and preconfiguredfeedback sets corresponding to the DCI transmitted by an eNB; and

step 302: feeding back aperiodically corresponding CSI by the UEaccording to the DCI and the feedback sets corresponding to the DCI.

In this embodiment, a manner of indicating the DCI and a manner ofclassifying the feedback sets are identical to those of Embodiment 1,the contents of which being incorporated herein, which shall not bedescribed herein any further.

In this embodiment, the UE determines the feedback sets according to thereceived DCI transmitted by the eNB, and performs aperiodic feedback ofthe corresponding CSI according to the contents indicated by thefeedback sets. Wherein, if 2-bit information of the DCI is 00, itdenotes that aperiodic report is not triggered. As the embodiments ofthe present invention are addressed to cases where aperiodic report istriggered, in the following description, a case where 2-bit informationof the DCI is 00 is excluded, except otherwise specified.

In this embodiment, assuming that 2-bit information, 01, 10 and 11, ofthe DCI, respectively denote to trigger feedback sets 1, 2 and 3configured by a high layer, if the DCI received by the UE is 10, thefeedback set 2 is triggered, and the UE performs aperiodic feedback ofthe corresponding CSI according to the contents indicated by thefeedback set 2 configured by the high layer. For example, if thefeedback set 2 configured by the high layer indicates a triggeredtransmitting point via bitmaps of N bits (N is the size of a CoMPmeasurement set) of RRC signaling, the UE reports only a CSI set towhich the triggered transmitting point corresponds; if the feedback set2 configured by the high layer indicates a CSI-RS of non-zero power viabitmaps of N bits of RRC signaling, the UE reports only a CSI set towhich the CSI-RS of non-zero power corresponds; if the feedback set 2configured by the high layer indicates a triggered CSI set via bitmapsof M bits (M is a CSI set configured by the high layer for the aperiodicfeedback) of RRC signaling, the UE reports only the triggered CSI set;and if the feedback set 2 configured by the high layer indicatesinterference types needing to be reported via 2^((N-1)) bits of RRCsignaling, the UE reports only the CSI sets to which the interferencetypes correspond.

By using the method of this embodiment, the UE selectively performsreport according to conditions defined by the feedback sets, instead ofreporting all the CSI (multiple pieces of CSI corresponding to differenttransmitting points and interference assumption conditions), therebysolving the problem of large feedback overhead due to that multiplepieces of CSI corresponding to different transmitting points andinterference assumption conditions need to be reported in CoMPtransmission, and realizing a relatively good tradeoff between feedbackflexibility and system signaling overhead.

Scenario of Jointing CoMP and CA where Aperiodic Feedback is Triggeredin a User Search Space

In an LTE-A system, a carrier aggregation (CA) technology may be jointedwith CoMP to further improve transmission efficiency of UE. In thisembodiment, triggering the UE to perform aperiodic report of CSI isachieved by independently configuring or jointly configuring.

Embodiment 3

An embodiment of the present invention further provides a method fortriggering aperiodic feedback in coordinated multipoint transmission, inwhich triggering UE to perform aperiodic report of CSI is achieved byindependently configuring. FIG. 4 is a flowchart of the method.Referring to FIG. 4, the method includes:

step 401: transmitting, by an eNB to UE, first DCI and preconfiguredfeedback sets corresponding to the first DCI, so that the UEaperiodically feeds back CSI of corresponding carrier aggregation (CA)according to the first DCI and the feedback sets corresponding to thefirst DCI; and

step 402: transmitting, by the eNB to the UE, second DCI andpreconfigured feedback sets corresponding to the second DCI, so that theUE aperiodically feeds back CSI of corresponding coordinated multipointtransmission (CoMP) according to the second DCI and the feedback setscorresponding to the second DCI.

In this embodiment, the preconfigured feedback sets corresponding to thesecond DCI may be classified according to a triggered transmitting pointor a CSI-RS of non-zero power, or may be classified according toconfigured CSI, or may be classified according to an interference type.A particular manner of classification and a manner of indicatingsignaling are identical to those in Embodiment 1, the contents of whichbeing incorporated herein, which shall not be described herein anyfurther.

In an embodiment, the first DCI and the second DCI are respectively1-bit information, and the method of this embodiment reuses current2-bit DCI signaling, in which 1 bit (the second DCI) is used to triggerCoMP aperiodic report, and the other bit (the first DCI) is used totrigger CA aperiodic report.

For example, 0x denotes that the CoMP aperiodic report is not triggered,1x denotes that a set 1 configured by RRC for CoMP aperiodic feedback istriggered, x0 denotes that the CA aperiodic report is not triggered, andx1 denotes that a set 2 configured by RRC for CA aperiodic feedback istriggered.

In another embodiment, the first DCI and the second DCI are respectively2-bit information, and the method of this embodiment triggers CoMP byadding DCI signaling of 2 bits, and the original DCI signaling of 2 bitsis used to trigger CA aperiodic report.

In this embodiment, indication manners of the first DCI and the secondDCI are identical to those in Embodiment 1. For example, 00 indicatesthat aperiodic feedback is not triggered, and 01, 10 and 11 indicatethat aperiodic feedback of feedback set 1, feedback set 2 and feedbackset 3, configured by a high layer, is triggered; or 11 indicates thataperiodic feedback is not triggered, 01 indicates that aperiodicfeedback of CSI of an anchor cell (a primary cell or a specific singlecell) is triggered, and 10 and 11 indicate that aperiodic feedback offeedback set 1 and feedback set 2 configured by a high layer istriggered.

In this embodiment, feedback sets corresponding to the first DCI andfeedback sets corresponding to the second DCI may be configured via RRCsignaling by using the method of Embodiment 1, the contents of whichbeing incorporated herein, which shall not be described herein anyfurther. For example, the feedback sets corresponding to the first DCIare indicated via 8-bit RRC signaling, and the feedback setscorresponding to the second DCI are indicated via idle bits in the 8-bitRRC signaling or newly-added RRC signaling (such as 2a or 2b).

By using the method of this embodiment to trigger the UE to performaperiodic feedback, the problem of large feedback overhead due to thatmultiple pieces of CSI corresponding to different transmitting pointsand interference assumptions need to be reported in joint transmissionof CA and CoMP is solved, and a relatively good tradeoff betweenfeedback flexibility and system signaling overhead is achieved.

Embodiment 4

An embodiment of the present invention further provides a method fortriggering aperiodic feedback in coordinated multipoint transmission,which is processing at a UE side corresponding to the method ofEmbodiment 3. FIG. 5 is a flowchart of the method. Referring to FIG. 5,the method includes:

step 501: receiving, by UE, first DCI and preconfigured feedback setscorresponding to the first DCI transmitted by an eNB;

step 502: feeding back aperiodically CSI of corresponding CA by the UEaccording to the first DCI and the feedback sets corresponding to thefirst DCI;

step 503: receiving, by the UE, second DCI and preconfigured feedbacksets corresponding to the second DCI transmitted by the eNB; and

step 504: feeding back aperiodically CSI of corresponding CoMP by the UEaccording to the second DCI and the feedback sets corresponding to thesecond DCI.

In this embodiment, manners of indicating the first DCI and the secondDCI are identical to those of Embodiment 3, the contents of which beingincorporated herein, which shall not be described herein any further.

In this embodiment, the preconfigured feedback sets corresponding to thesecond DCI may be classified according to a triggered transmitting pointor a CSI-RS of non-zero power, or may be classified according toconfigured CSI, or may be classified according to an interference typeneeding to be reported. A particular manner of classifying of a feedbackset and a manner of signaling indication of a feedback set are identicalto those in Embodiment 1, the contents of which being incorporatedherein, which shall not be described herein any further.

In this embodiment, the UE determines the feedback sets corresponding tothe first DCI according to the received first DCI transmitted by theeNB, and performs aperiodic feedback of the CSI of corresponding CAaccording to the contents indicated by the feedback sets correspondingto the first DCI. Furthermore, the UE determines the feedback setscorresponding to the second DCI according to the received second DCItransmitted by the eNB, and performs aperiodic feedback of the CSI ofcorresponding CoMP according to the contents indicated by the feedbacksets corresponding to the second DCI.

Therefore, the UE may determine corresponding feedback sets of CA andcorresponding feedback sets of CoMP according to the received first DCIand second DCI, perform aperiodic feedback of the CSI of CA according tothe feedback sets of CA, and perform aperiodic feedback of the CSI ofCoMP according to the feedback sets of CoMP.

By using the method of this embodiment, the problem of large feedbackoverhead due to that multiple pieces of CSI corresponding to differenttransmitting points and interference assumptions need to be reported injoint transmission of CA and CoMP is solved, and a relatively goodtradeoff between feedback flexibility and system signaling overhead isachieved.

Embodiment 5

An embodiment of the present invention further provides a method fortriggering aperiodic feedback in coordinated multipoint transmission, inwhich triggering UE to perform aperiodic report of CSI is achieved byjointly configuring. FIG. 6 is a flowchart of the method. Referring toFIG. 6, the method includes:

step 601: transmitting, by an eNB to UE, DCI and preconfigured feedbacksets corresponding to the DCI, so that the UE aperiodically feeds backCSI of corresponding CA and CoMP according to the DCI and the feedbacksets corresponding to the DCI.

In this embodiment, a manner of indicating the DCI is identical to thatof Embodiment 1, the contents of which being incorporated herein, whichshall not be described herein any further.

In this embodiment, the preconfigured feedback sets corresponding to theDCI may be classified according to a triggered transmitting point or aCSI-RS of non-zero power, or may be classified according to configuredCSI, and a particular method of classification is identical to that ofEmbodiment 1, the contents of which being incorporated herein, whichshall not be described herein any further. Furthermore, thepreconfigured feedback sets corresponding to the DCI are indicated viaRRC signaling, the RRC signaling including a carrier indication bitcorresponding to each triggered transmitting point or each piece ofconfigured CSI.

In this embodiment, multiple feedback sets configured via RRC signalingare triggered via 2-bit DCI, the feedback sets being determined by CSIjoining carriers and CoMP.

In an embodiment, when the feedback sets are classified according to atriggered transmitting point or a CSI-RS of non-zero power, that is, thetransmitting point is taken as a content of the aperiodic feedback, theRRC signaling used to indicate the feedback sets is achieved byconcatenated configuration of multiple transmitting points, that is, theRRC signaling includes a carrier indication bit corresponding to eachtriggered transmitting point, as shown in FIG. 7a . In FIG. 7a ,selection of subcarriers from 8 bits is taken as an example. Actually,as an existing LTE-A system supports at most 5 subcarriers,corresponding to each triggered TP, subcarriers available for selectionmay only be indicated by 5 bits.

In another embodiment, when the feedback sets are classified accordingto configured CSI, that is, the CSI is taken as a content of theaperiodic feedback, the RRC signaling used to indicate the feedback setsis achieved by concatenated configuration of the CSI, that is, the RRCsignaling includes a carrier indication bit corresponding to each pieceof configured CSI, as shown in FIG. 7b . In FIG. 7b , selection ofsubcarriers from 8 bits is also taken as an example, likewise, as anexisting LTE-A system supports at most 5 subcarriers, corresponding toeach piece of configured CSI, subcarriers available for selection mayonly be indicated by 5 bits.

By using the method of this embodiment to trigger the UE to perform theaperiodic feedback, the problem of large feedback overhead due to thatmultiple pieces of CSI corresponding to different transmitting pointsand interference assumptions need to be reported in joint transmissionof CA and CoMP is solved, and a relatively good tradeoff betweenfeedback flexibility and system signaling overhead is achieved.

Embodiment 6

An embodiment of the present invention further provides a method fortriggering aperiodic feedback in coordinated multipoint transmission,which is processing at a UE side corresponding to the method ofEmbodiment 5. FIG. 8 is a flowchart of the method. Referring to FIG. 8,the method includes:

step 801: receiving, by UE, DCI and preconfigured feedback setscorresponding to the DCI transmitted by an eNB; and

step 802: feeding back aperiodically CSI of corresponding CA and CoMP bythe UE according to the DCI and the feedback sets corresponding to theDCI.

In this embodiment, a manner of indicating the DCI is identical to thatof Embodiment 1, the contents of which being incorporated herein, whichshall not be described herein any further.

In this embodiment, the preconfigured feedback sets corresponding to theDCI may be classified according to a triggered transmitting point or aCSI-RS of non-zero power, or may be classified according to configuredCSI, and a particular method of classification is identical to that ofEmbodiment 1, the contents of which being incorporated herein, whichshall not be described herein any further. Furthermore, thepreconfigured feedback sets corresponding to the DCI are indicated viaRRC signaling, the RRC signaling including a carrier indication bitcorresponding to each triggered transmitting point or each piece ofconfigured CSI.

In this embodiment, after receiving the DCI transmitted by the eNB, theUE determines corresponding feedback sets according to the DCI, andperforms aperiodic feedback of corresponding CSI according to thecontents indicated by the feedback sets. Wherein, the feedback sets areindicated by the eNB via RRC signaling, and corresponding to differentclassification manners, the RRC signaling employs different indicationmanners. Particular indication manners are described in detail inEmbodiment 5, which shall not be described herein any further.

By using the method of this embodiment, the UE performs aperiodicfeedback of corresponding CSI according to the DCI transmitted by theeNB and the feedback sets indicated by the high layer (RRC signaling),thereby solving the problem of large feedback overhead due to thatmultiple pieces of CSI corresponding to different transmitting pointsand interference assumptions need to be reported in joint transmissionof CA and CoMP, and achieving a relatively good tradeoff betweenfeedback flexibility and system signaling overhead.

Embodiment 7

An embodiment of the present invention further provides a method fortriggering aperiodic feedback in coordinated multipoint transmission, inwhich triggering UE to perform aperiodic report of CSI is achieved byjointly configuring. FIG. 9 is a flowchart of the method. Referring toFIG. 9, the method includes:

step 901: transmitting, by an eNB to UE, DCI and preconfigured feedbacksets corresponding to the DCI, so that the UE aperiodically feeds backCSI of corresponding CA and CoMP according to the DCI and the feedbacksets corresponding to the DCI.

In this embodiment, a manner of indicating the DCI is identical to thatof Embodiment 1, the contents of which being incorporated herein, whichshall not be described herein any further.

In this embodiment, the preconfigured feedback sets corresponding to theDCI may be classified according to a triggered transmitting point or aCSI-RS of non-zero power, or may be classified according to configuredCSI, and a particular method of classification is identical to that ofEmbodiment 1, the contents of which being incorporated herein, whichshall not be described herein any further. Furthermore, in thisembodiment, the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating configured or activated carriers, and a TPindication bit for indicating a triggered TP corresponding to eachconfigured or activated carrier or a CSI indication bit for indicatingconfigured CSI corresponding to each configured or activated carrier, orthe RRC signaling including a carrier indication bit for indicatingconfigured or activated carriers, and a carrier indication bit forindicating a carrier corresponding to each triggered TP or configuredCSI. Wherein, if the carrier indication bit of the configured oractivated carriers has already existed, the RRC signaling does notinclude this part of contents.

In this embodiment, the multiple feedback sets configured via the RRCsignaling are also triggered via 2-bit DCI, and are determined by CSIjoining carriers and CoMP. However, different from Embodiment 5, the UEis configured with used carriers in the CA transmission, or somecarriers are activated. In this embodiment, the RRC signaling used toindicate the aperiodic feedback sets includes not only this part ofcarrier indication bits, but also the transmitting point indication bitsof the triggered transmitting points or the CSI indication bits of theconfigured CSI corresponding to the configured or activated carriers.That is, the carrier indication bits and the CoMP CSI feedbackinformation corresponding to the configured or activated carriers (TPindication bits of the triggered TPs or the CSI indication bits of theconfigured CSI) are concatenated into a piece of signaling.

In an embodiment, when the feedback sets are classified according to thetriggered transmitting points or the CSI-RS of non-zero power, that is,transmitting points are taken as contents of the aperiodic feedback, theRRC signaling used to indicate the feedback sets is achieved by thecarrier indication bits and the TP indication bits of the triggered TPscorresponding to each activated or configured carrier. As shown in FIG.10a , the RRC signaling includes carrier indication bits (the left ofthe plus sign in FIG. 10a ), in which three carriers are activated orconfigured for use, and corresponding to each of the three carriers, aTP indication bit of a triggered TP is configured. Referring to theright of the plus sign, assuming that the number of the triggeredtransmitting points is 3, each carrier needs information of 3 bits.

In another embodiment, when the feedback sets are classified accordingto the configured CSI, that is, CSI is taken as a content of theaperiodic feedback, the RRC signaling used to indicate the feedback setsis achieved by the carrier indication bits and the CSI indication bitsof the configured CSI corresponding to each activated or configuredcarrier. As shown in FIG. 10b , the RRC signaling includes carrierindication bits shown on the left of the plus sign and the CSIindication bits of the configured CSI corresponding to each activated orconfigured carrier shown on the right of the plus sign. Wherein,assuming that the number of the configured CSI sets is 5, each carrierneeds information of 5 bits.

In the above embodiments, a first concatenate of the RRC signaling beingthe carrier indication bits and the second concatenate being TPindication bits or CSI indication bits are taken as examples. Inparticular implementation, a method where a first concatenate is TPindication bits or CSI indication bits and the second concatenate iscarrier indication bits may also be employed. That is, the RRC signalingincludes carrier indication bits indicating the configured or activatedcarriers and carrier indication bits indicating a carrier correspondingto each triggered TP or configured CSI, and this embodiment is notlimited thereto.

By using the method of this embodiment to trigger the UE to perform theaperiodic feedback, the problem of large feedback overhead due to thatmultiple pieces of CSI corresponding to different transmitting pointsand interference assumptions need to be reported in joint transmissionof CA and CoMP is solved, and a relatively good tradeoff between systemflexibility and signaling overhead is achieved.

Embodiment 8

An embodiment of the present invention further provides a method fortriggering aperiodic feedback in coordinated multipoint transmission,which is processing at a UE side corresponding to the method ofEmbodiment 7. FIG. 11 is a flowchart of the method. Referring to FIG.11, the method includes:

step 1101: receiving, by UE, DCI and preconfigured feedback setscorresponding to the DCI transmitted by an eNB; and

step 1102: feeding back aperiodically CSI of corresponding CA and CoMPby the UE according to the DCI and the feedback sets corresponding tothe DCI.

In this embodiment, a manner of indicating the DCI is identical to thatof Embodiment 1, the contents of which being incorporated herein, whichshall not be described herein any further.

In this embodiment, the preconfigured feedback sets corresponding to theDCI may be classified according to a triggered transmitting point or aCSI-RS of non-zero power, or may be classified according to configuredCSI, and a particular method of classification is identical to that ofEmbodiment 1, the contents of which being incorporated herein, whichshall not be described herein any further. Furthermore, in thisembodiment, the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating configured or activated carriers, and a TPindication bit for indicating a triggered TP corresponding to eachconfigured or activated carrier or a CSI indication bit for indicatingconfigured CSI corresponding to each configured or activated carrier, orthe RRC signaling including a bit for indicating configured or activatedcarriers, and a bit for indicating carriers corresponding to eachtriggered TP or configured CSI.

In this embodiment, after receiving the DCI transmitted by the eNB, theUE determines corresponding feedback sets according to the DCI, andperforms aperiodic feedback of corresponding CSI according to thecontents indicated by the feedback sets. Wherein, the feedback sets areindicated by the eNB via RRC signaling, and corresponding to differentclassification manners, the RRC signaling employs different indicationmanners. Particular indication manners are described in detail inEmbodiment 7, which shall not be described herein any further.

By using the method of this embodiment, the UE performs aperiodicfeedback of corresponding CSI according to the DCI transmitted by theeNB and the feedback sets indicated by the high layer (RRC signaling),thereby solving the problem of large feedback overhead due to thatmultiple pieces of CSI corresponding to different transmitting pointsand interference assumptions need to be reported in joint transmissionof CA and CoMP, and achieving a relatively good tradeoff betweenfeedback flexibility and system signaling overhead.

Embodiment 9

An embodiment of the present invention further provides a method fortriggering aperiodic feedback in coordinated multipoint transmission, inwhich triggering UE to perform aperiodic report of CSI is also achievedby jointly configuring. FIG. 12 is a flowchart of the method. Referringto FIG. 12, the method includes:

step 1201: transmitting, by an eNB to UE, DCI and preconfigured feedbacksets corresponding to the DCI, so that the UE aperiodically feeds backCSI of corresponding CA and CoMP according to the DCI and the feedbacksets corresponding to the DCI.

In this embodiment, a manner of indicating the DCI is identical to thatof Embodiment 1, the contents of which being incorporated herein, whichshall not be described herein any further.

In this embodiment, the preconfigured feedback sets corresponding to theDCI may be classified according to a triggered transmitting point or aCSI-RS of non-zero power, or may classified according to configured CSI,and a particular method of classification is identical to that ofEmbodiment 1, the contents of which being incorporated herein, whichshall not be described herein any further. Furthermore, in thisembodiment, the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating triggered aperiodically fed back carriers,and a TP indication bit for indicating a triggered TP corresponding toeach triggered carrier or a CSI indication bit for indicating configuredCSI corresponding to each triggered carrier, or the RRC signalingincluding a carrier indication bit for indicating triggeredaperiodically fed back carriers, and a carrier indication bit forindicating a carrier corresponding to each triggered TP or configuredCSI.

In this embodiment, the multiple feedback sets configured via the RRCsignaling are also triggered via 2-bit DCI, and are determined by CSIjoining carriers and CoMP. However, different from Embodiment 7, the UEis not configured with used carriers or does not activate the usedcarriers in the CA transmission, but triggers use of some carriers inoperation. In this embodiment, the RRC signaling used to indicate theaperiodic feedback sets includes carrier indication bits of this part oftriggered carriers and the transmitting point indication bits of thetriggered transmitting points or the CSI indication bits of theconfigured CSI corresponding to the triggered carriers. That is, thecarrier indication bits of the triggered carriers and the CoMP CSIfeedback information corresponding to the triggered carriers (TPindication bits of the triggered TPs or the CSI indication bits of theconfigured CSI) are concatenated into a piece of signaling.

In an embodiment, when the feedback sets are classified according to thetriggered transmitting points or the CSI-RS of non-zero power, that is,transmitting points are taken as contents of the aperiodic feedback, theRRC signaling used to indicate the feedback sets is achieved by thecarrier indication bits and the TP indication bits of the triggered TPscorresponding to each triggered carrier. Wherein, as the number of thetriggered carriers is variable, the corresponding RRC signaling used toindicate the aperiodic feedback sets is also variable. As shown in FIG.13a , the RRC signaling includes carrier indication bits (the left ofthe plus sign in FIG. 13a ), in which three carriers (a 0-th, a firstand a third carriers) are triggered, and corresponding to each of thethree carriers, a TP indication bit of a triggered TP is configured.Referring to the right of the plus sign, assuming that the number of thetriggered transmitting points is 3, each carrier needs information of 3bits.

In another embodiment, when the feedback sets are classified accordingto the configured CSI, that is, CSI is taken as a content of theaperiodic feedback, the RRC signaling used to indicate the feedback setsis achieved by the carrier indication bits and the CSI indication bitsof the configured CSI corresponding to each triggered carrier. As shownin FIG. 13b , the RRC signaling includes carrier indication bits shownon the left of the plus sign and the CSI indication bits of theconfigured CSI corresponding to each triggered carrier shown on theright of the plus sign. Wherein, assuming that the number of theconfigured CSI sets is 5, each carrier needs information of 5 bits.

In the above embodiments, a first concatenate of the RRC signaling beingthe carrier indication bits and the second concatenate being TPindication bits or CSI indication bits are taken as examples. Inparticular implementation, a method where a first concatenate is TPindication bits or CSI indication bits and the second concatenate iscarrier indication bits may also be employed. That is, the RRC signalingincludes carrier indication bits indicating the triggered carriers andcarrier indication bits indicating a carrier corresponding to eachtriggered TP or configured CSI, and this embodiment is not limitedthereto.

By using the method of this embodiment to trigger the UE to perform theaperiodic feedback, the problem of large feedback overhead due to thatmultiple pieces of CSI corresponding to different transmitting pointsand interference assumptions need to be reported in joint transmissionof CA and CoMP is solved, and a relatively good tradeoff betweenfeedback flexibility and system signaling overhead is achieved.

Embodiment 10

An embodiment of the present invention further provides a method fortriggering aperiodic feedback in coordinated multipoint transmission,which is processing at a UE side corresponding to the method ofEmbodiment 9. FIG. 14 is a flowchart of the method. Referring to FIG.14, the method includes:

step 1401: receiving, by UE, DCI and preconfigured feedback setscorresponding to the DCI transmitted by an eNB; and

step 1402: feeding back aperiodically CSI of corresponding CA and CoMPby the UE according to the DCI and the feedback sets corresponding tothe DCI.

In this embodiment, a manner of indicating the DCI is identical to thatof Embodiment 1, the contents of which being incorporated herein, whichshall not be described herein any further.

In this embodiment, the preconfigured feedback sets corresponding to theDCI may be classified according to a triggered transmitting point or aCSI-RS of non-zero power, or may classified according to configured CSI,and a particular method of classification is identical to that ofEmbodiment 1, the contents of which being incorporated herein, whichshall not be described herein any further. Furthermore, in thisembodiment, the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating triggered aperiodically fed back carriers,and a TP indication bit for indicating a triggered TP corresponding toeach triggered carrier or a CSI indication bit for indicating configuredCSI corresponding to each triggered carrier, or the RRC signalingincluding a carrier indication bit for indicating triggeredaperiodically fed back carriers, and a carrier indication bit forindicating a carrier corresponding to each triggered TP or configuredCSI.

In this embodiment, after receiving the DCI transmitted by the eNB, theUE determines corresponding feedback sets according to the DCI, andperforms aperiodic feedback of corresponding CSI according to thecontents indicated by the feedback sets. Wherein, the feedback sets areindicated by the eNB via RRC signaling, and corresponding to differentclassification manners, the RRC signaling employs different indicationmanners. Particular indication manners are described in detail inEmbodiment 9, which shall not be described herein any further.

By using the method of this embodiment, the UE performs aperiodicfeedback of corresponding CSI according to the DCI transmitted by theeNB and the feedback sets indicated by the high layer (RRC signaling),thereby solving the problem of large feedback overhead due to thatmultiple pieces of CSI corresponding to different transmitting pointsand interference assumptions need to be reported in joint transmissionof CA and CoMP, and achieving a relatively good tradeoff betweenfeedback flexibility and system signaling overhead.

Embodiment 11

An embodiment of the present invention further provides a method fortriggering aperiodic feedback in coordinated multipoint transmission, inwhich triggering UE to perform aperiodic report of CSI is also achievedby jointly configuring. FIG. 15 is a flowchart of the method. Referringto FIG. 15, the method includes:

step 1501: transmitting, by an eNB to UE, DCI and preconfigured feedbacksets corresponding to the DCI, so that the UE aperiodically feeds backCSI of corresponding CA and CoMP according to the DCI and the feedbacksets corresponding to the DCI.

In this embodiment, a manner of indicating the DCI is identical to thatof Embodiment 1, the contents of which being incorporated herein, whichshall not be described herein any further.

In this embodiment, the preconfigured feedback sets corresponding to theDCI may be classified according to a triggered transmitting point or aCSI-RS of non-zero power, or may be classified according to configuredCSI, and a particular method of classification is identical to that ofEmbodiment 1, the contents of which being incorporated herein, whichshall not be described herein any further. Furthermore, in thisembodiment, the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating triggered carriers, and a TP indicationbit or a CSI indication bit for indicating fed back contentscorresponding to each triggered carrier.

In this embodiment, in order to lower signaling overhead, it is assumedthat all the triggered aperiodically fed back contents in all thetriggered carriers are identical, then the RRC signaling used forindicating the aperiodically fed back feedback sets includes only thecarrier indication bits of the triggered carriers and the feedbackcontents fed back in the triggered carriers (TP indication bits or CSIindication bits).

In an embodiment, as shown in FIG. 16a , in a classification mannertaking a TP as an aperiodically fed back content, assuming that acarrier 0 and a carrier 1 are triggered and the triggered aperiodicallyfed back contents in the carriers are identical, the RRC signalingincludes only a carrier indication bit and a corresponding TP indicationbit.

In another embodiment, as shown in FIG. 16b , in a classification mannertaking CSI as an aperiodically fed back content, assuming that thecarrier 0 and the carrier 1 are triggered and the triggeredaperiodically fed back contents in the carriers are identical, the RRCsignaling includes only a carrier indication bit and a corresponding CSIindication bit.

By using the method of this embodiment to trigger the UE to perform theaperiodic feedback, the signaling overhead is low, and the problem oflarge feedback overhead due to that multiple pieces of CSI correspondingto different transmitting points and interference assumptions need to bereported in joint transmission of CA and CoMP is solved, and arelatively good tradeoff between feedback flexibility and systemsignaling overhead is achieved.

Embodiment 12

An embodiment of the present invention further provides a method fortriggering aperiodic feedback in coordinated multipoint transmission,which is processing at a UE side corresponding to the method ofEmbodiment 11. FIG. 17 is a flowchart of the method. Referring to FIG.17, the method includes:

step 1701: receiving, by UE, DCI and preconfigured feedback setscorresponding to the DCI transmitted by an eNB; and

step 1702: feeding back aperiodically CSI of corresponding CA and CoMPby the UE according to the DCI and the feedback sets corresponding tothe DCI.

In this embodiment, a manner of indicating the DCI is identical to thatof Embodiment 1, the contents of which being incorporated herein, whichshall not be described herein any further.

In this embodiment, the preconfigured feedback sets corresponding to theDCI may be classified according to a triggered transmitting point or aCSI-RS of non-zero power, or may be classified according to configuredCSI, and a particular method of classification is identical to that ofEmbodiment 1, the contents of which being incorporated herein, whichshall not be described herein any further. Furthermore, in thisembodiment, the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating triggered carriers, and a TP indicationbit or a CSI indication bit for indicating fed back contentscorresponding to each triggered carrier.

In this embodiment, after receiving the DCI transmitted by the eNB, theUE determines corresponding feedback sets according to the DCI, andperforms aperiodic feedback of corresponding CSI according to thecontents indicated by the feedback sets. Wherein, the feedback sets areindicated by the eNB via RRC signaling, and corresponding to differentclassification manners, the RRC signaling employs different indicationmanners. Particular indication manners are described in detail inEmbodiment 11, which shall not be described herein any further.

By using the method of this embodiment, the UE performs aperiodicfeedback of corresponding CSI according to the DCI transmitted by theeNB and the feedback sets indicated by the high layer (RRC signaling),the signaling is low, the problem of large feedback overhead due to thatmultiple pieces of CSI corresponding to different transmitting pointsand interference assumptions need to be reported in joint transmissionof CA and CoMP is solved, and a relatively good tradeoff betweenfeedback flexibility and system signaling overhead is achieved.

Scenario where Aperiodic Feedback is Triggered in a Common Search SpaceEmbodiment 13

An embodiment of the present invention further provides a method fortriggering aperiodic feedback in coordinated multipoint transmission, inwhich aperiodic feedback of CSI is triggered in a common search space.FIG. 18 is a flowchart of the method. Referring to FIG. 18, the methodincludes:

step 1801: transmitting dynamic control information (DCI) by an eNB toUE, so that the UE aperiodically feeds back corresponding channel stateinformation according to the DCI and preconfigured feedback committedinformation corresponding to the DCI.

In this embodiment, the preconfigured feedback committed informationcorresponding to the DCI is, for example, feeding back all the CSI of afirst CSI-RS resource of non-zero power, or feeding back first CSI in anaperiodic feedback CSI set, or feeding back first CSI in a triggeredaperiodic feedback CSI set.

In this embodiment, when the aperiodic feedback is triggered via thecommon search space, in order to meet a limit of the number of bits ofsignaling, only DCI of 1 bit is used for triggering the aperiodicfeedback. Wherein, 0 denotes that aperiodic report is not triggered, and1 denotes that aperiodic report is triggered. And wherein, “1” may havemultiple indication manners, such as a feedback set 1 configured by ahigh layer. The feedback set 1 may also be classified by using theclassification method of Embodiment 1, and its particular high-layerindication method may also use the method of Embodiment 1; for example,corresponding to different classification methods, different RRCsignaling designs are employed. That is, the method of Embodiment 1 mayalso be applicable to a scenario where aperiodic feedback is triggeredin a common search space. Different from Embodiment 1 in which theaperiodic feedback is indicated via 2-bit information of DCI, in such ascenario in this embodiment, the aperiodic feedback is indicated via1-bit information of DCI. However, corresponding to the aperiodicallyfed back feedback sets, the method in Embodiment 1 may be followed inthis embodiment. As the methods of classification of feedback sets andhigh-layer indication of feedback sets are described in Embodiment 1,which shall not be described herein any further.

In this embodiment, in consideration that the UE uses the common searchspace to trigger the aperiodic report, and a channel state of the UE maybe relatively poor, such as being in a state of high speed, a robusttransmission mode needs to be employed in actual transmission by the UE,such as turning back to a transmission mode in a single cell; or the UEis in a state of RRC reconfiguration, and in the RRC reconfigurationprocess, a CSI-RS resource of a measurement set changes, hence, CSI insome states is not accurate; furthermore, when an uplink channel stateis not ideal, feedback overhead that can be supported should not be toohigh.

Taking the above cases into account, in the embodiment of the presentinvention, aperiodically reported contents are agreed by preconfiguringfeedback committed information corresponding to the DCI by the eNB andthe UE. And when the eNB triggers the UE via the 1-bit DCI information“1” to perform aperiodic feedback of CSI in the common search space, theUE fixedly feeds back CSI of a certain cell according to thepreconfigured feedback committed information. In an embodiment, thefeedback committed information indicates to feed back all the CSI of afirst CSI-RS resource of non-zero power, the CSI corresponding to CSI ofa single cell. In another embodiment, the feedback committed informationindicates to feed back first CSI in all CSI, the first CSI correspondingto interference-enabled CSI of a single cell. Hence, the above problemmay be solved, and the aperiodic report may be triggered efficiently.

In this embodiment, if it is a scenario of jointing CoMP and CA,indication in a downlink carrier corresponding to triggering an uplinkcarrier may be RRC configuration, or may be a predetermined fixed CSI orTP resource, or an anchor CSI or TP resource configured by the eNB forthe user.

By using the method of this embodiment to trigger the UE to perform theaperiodic feedback, several problems occurred in triggering aperiodicreport by the UE in a common search space may be solved, the signalingoverhead is low, and a relatively good tradeoff between feedbackflexibility and system signaling overhead is achieved.

Embodiment 14

An embodiment of the present invention further provides a method fortriggering aperiodic feedback in coordinated multipoint transmission,which is processing at a UE side corresponding to the method ofEmbodiment 13. FIG. 19 is a flowchart of the method. Referring to FIG.19, the method includes:

step 1901: receiving, by UE, DCI transmitted by an eNB; and

step 1902: feeding back aperiodically corresponding CSI by the UEaccording to the DCI and preconfigured feedback committed informationcorresponding to the DCI;

In this embodiment, the preconfigured feedback committed informationcorresponding to the DCI is feeding back all the CSI of a first CSI-RSresource of non-zero power, or feeding back first CSI in an aperiodicfeedback CSI set, or feeding back first CSI in a triggered aperiodicfeedback CSI set.

With the method of this embodiment, as whether the aperiodic feedback isperformed is indicated via only 1-bit information of DCI, the UEperforms corresponding aperiodic feedback according to an agreement madebetween it and the eNB in determining to perform aperiodic feedbackaccording to the DCI. Therefore, several problems occurred in triggeringaperiodic report by the UE in a common search space may be solved, thesignaling overhead is low, and a relatively good tradeoff betweenfeedback flexibility and system signaling overhead is achieved.

Similar to Embodiment 13, as the eNB may also indicate fed back contentsin a manner of preconfiguring feedback sets corresponding to the 1-bitDCI in such a scenario, at the UE side, the method of Embodiment 2 maybe employed to achieve aperiodic feedback.

Embodiment 15

An embodiment of the present invention further provides a method fortriggering aperiodic feedback in coordinated multipoint transmission, inwhich aperiodic feedback is also triggered in a common search space.FIG. 20 is a flowchart of the method. Referring to FIG. 20, the methodincludes:

step 2001: transmitting, by an eNB to UE, dynamic control information(DCI) and a preconfigured anchor CSI resource, so that the UEaperiodically feeds back corresponding CSI according to the DCI and theanchor CSI resource.

In this embodiment, the preconfigured anchor CSI resource is indicatedvia RRC signaling, the RRC signaling including log₂(N) bits, N bits,log₂(M) bits, or M bits, for indicating the anchor CSI resource; where Nis the size of a CoMP measurement set, and M is the size of a configuredCSI set.

In this embodiment, the eNB preconfigures an anchor CSI resource, theanchor CSI resource being specifically used to triggering aperiodicfeedback, especially for use in triggering aperiodic feedback in acommon search space. Wherein, the anchor CSI resource may be selected bythe eNB according to RSRP (reference signal receiving power) and/or RSRQ(reference signal receiving quality), and this embodiment is not limitedthereto. The anchor CSI resource may be at least one CSI resource towhich a CSI-RS of non-zero power corresponds, and may also be at leastone CSI resource in an aperiodically fed back CSI set.

In this embodiment, the anchor CSI resource may be indicated via RRCsignaling. In an embodiment, the CSI resource is differentiatedaccording to a triggered TP (a CSI-RS of non-zero power), and the RRCsignaling indicates the triggered TP (CSI-RS of non-zero power) vialog₂(N) bits, so that the UE determines the anchor CSI resource from CSIresources to which N TPs (CSI-RSs of non-zero power) correspond, where,N is the size of a CoMP measurement set; or the RRC signaling indicatesthe anchor CSI resource via N bits, and at this moment, a bitmap mannermay be used. In another embodiment, the CSI resource is differentiatedaccording to configured CSI, and the RRC signaling indicates a positionof the anchor CSI resource in a CSI set configured by the eNB foraperiodically fed back via log₂(M) bits, or indicates the position via abitmap of M bits, M being the size of a CSI set configured by the eNBfor aperiodic feedback.

By using the method of this embodiment to trigger the UE to perform theaperiodic feedback, several problems occurred in triggering aperiodicreport by the UE in a common search space may be solved, and thesignaling overhead is low.

Embodiment 16

An embodiment of the present invention further provides a method fortriggering aperiodic feedback in coordinated multipoint transmission,which is processing at a UE side corresponding to the method ofEmbodiment 15. FIG. 21 is a flowchart of the method. Referring to FIG.21, the method includes:

step 2101: receiving, by UE, DCI and a preconfigured anchor CSI resourcetransmitted by an eNB; and

step 2102: feeding back aperiodically corresponding CSI by the UEaccording to the DCI and the anchor CSI resource.

In this embodiment, the anchor CSI resource is at least one CSI resourceto which a CSI-RS of non-zero power corresponds, or at least one CSIresource in an aperiodic feedback CSI set.

In this embodiment, the preconfigured anchor CSI resource is indicatedvia RRC signaling, the RRC signaling including log₂(N) bits, N bits,log₂(M) bits, or M bits, for indicating the anchor CSI resource; where Nis the size of a CoMP measurement set, and M is the size of a configuredCSI set; wherein when the RRC signaling indicates the anchor CSIresource via N bits or M bits, the indication is performed in a mannerof a bitmap.

With the method of this embodiment, as whether the aperiodic feedback isperformed is indicated via only 1-bit information of DCI, the UEperforms corresponding aperiodic feedback according to the anchor CSIresource preconfigured by the eNB in determining to perform aperiodicfeedback according to the DCI. Therefore, several problems occurred intriggering aperiodic report by the UE in a common search space may besolved, and the signaling overhead is low.

Corresponding to the method of Embodiment 1, an embodiment of thepresent invention further provides an eNB. As the principle of the eNBfor solving problems is similar to that of the method in Embodiment 1,the implementation of the method in Embodiment 1 is referred to for theimplementation of the eNB, and the repeated parts shall not be describedany further. FIG. 22 is a schematic diagram of the structure of the eNB.Referring to FIG. 22, the eNB includes:

a transmitting unit 221 configured to transmit to UE, 1-bit or 2-bitdynamic control information (DCI) and feedback sets corresponding to theDCI preconfigured via RRC signaling, so that the UE aperiodically feedsback corresponding CSI according to the DCI and the feedback setscorresponding to the DCI.

Wherein, the feedback sets corresponding to the DCI preconfigured viaRRC signaling are classified according to a triggered transmitting pointor a CSI-RS of non-zero power, or are classified according to configuredCSI, or are classified according to an interference type.

Wherein, the number of the feedback sets corresponding to the 1-bit DCIis 1, and the number of the feedback sets corresponding to the 2-bit DCIis 3 or 2.

By using the eNB of this embodiment to trigger the UE to perform theaperiodic feedback of CSI, a relatively good tradeoff between feedbackflexibility and system signaling overhead may be achieved.

Corresponding to the method of Embodiment 2, an embodiment of thepresent invention further provides user equipment (UE). As the principleof the UE for solving problems is similar to that of the method inEmbodiment 2, the implementation of the method in Embodiment 2 isreferred to for the implementation of the UE, and the repeated partsshall not be described any further. FIG. 23 is a schematic diagram ofthe structure of the UE. Referring to FIG. 23, the UE includes:

a receiving unit 231 configured to receive 1-bit or 2-bit DCI andfeedback sets corresponding to the DCI preconfigured via RRC signalingtransmitted by an eNB; and

a reporting unit 232 configured to feed back aperiodically correspondingCSI according to the DCI and the feedback sets corresponding to the DCI.

Wherein the feedback sets corresponding to the DCI preconfigured via RRCsignaling are classified according to a triggered transmitting point ora CSI-RS of non-zero power, or are classified according to configuredCSI, or are classified according to an interference type.

Wherein, the number of the feedback sets corresponding to the 1-bit DCIis 1, and the number of the feedback sets corresponding to the 2-bit DCIis 3 or 2.

By using the UE of this embodiment to perform the aperiodic feedback ofCSI according to the triggering by the eNB, a relatively good tradeoffbetween feedback flexibility and system signaling overhead may beachieved.

Corresponding to the method of Embodiment 3, an embodiment of thepresent invention further provides an eNB. As the principle of the eNBfor solving problems is similar to that of the method in Embodiment 3,the implementation of the method in Embodiment 3 is referred to for theimplementation of the eNB, and the repeated parts shall not be describedany further. FIG. 24 is a schematic diagram of the structure of the eNB.Referring to FIG. 24, the eNB includes:

a first transmitting unit 241 configured to transmit to the UE, 1-bit or2-bit first DCI and feedback sets corresponding to the first DCIpreconfigured via RRC signaling, so that the UE aperiodically feeds backCSI of corresponding CA according to the first DCI and the feedback setscorresponding to the first DCI; and

a second transmitting unit 242 configured to transmit to the UE, 1-bitor 2-bit second DCI and feedback sets corresponding to the second DCIpreconfigured via RRC signaling, so that the UE aperiodically feeds backCSI of corresponding CoMP according to the second DCI and the feedbacksets corresponding to the second DCI.

Wherein, the feedback sets corresponding to the second DCI preconfiguredvia RRC signaling are classified according to a triggered transmittingpoint or a CSI-RS of non-zero power, or are classified according toconfigured CSI, or are classified according to an interference type.

Wherein, the number of the feedback sets corresponding to the 1-bitfirst DCI is 1, the number of the feedback sets corresponding to the1-bit second DCI is 1, the number of the feedback sets corresponding tothe 2-bit first DCI is 3 or 2, and the number of the feedback setscorresponding to the 2-bit second DCI is 3 or 2.

By using the eNB of this embodiment to trigger the UE to perform theaperiodic feedback of CSI, a relatively good tradeoff between feedbackflexibility and system signaling overhead may be achieved.

Corresponding to the method of Embodiment 4, an embodiment of thepresent invention further provides user equipment (UE). As the principleof the UE for solving problems is similar to that of the method inEmbodiment 4, the implementation of the method in Embodiment 4 isreferred to for the implementation of the UE, and the repeated partsshall not be described any further. FIG. 25 is a schematic diagram ofthe structure of the UE. Referring to FIG. 25, the UE includes:

a first receiving unit 251 configured to receive 1-bit or 2-bit firstDCI and feedback sets corresponding to the first DCI preconfigured viaRRC signaling transmitted by an eNB;

a first reporting unit 252 configured to feed back aperiodically CSI ofcorresponding CA according to the first DCI and the feedback setscorresponding to the first DCI;

a second receiving unit 253 configured to receive 1-bit or 2-bit secondDCI and preconfigured feedback sets corresponding to the second DCItransmitted by the eNB; and

a second reporting unit 254 configured to feed back aperiodically CSI ofcorresponding CoMP according to the second DCI and the feedback setscorresponding to the second DCI.

Wherein, the preconfigured feedback sets corresponding to the second DCIare classified according to a triggered transmitting point or a CSI-RSof non-zero power, or are classified according to configured CSI, or areclassified according to an interference type.

Wherein, the number of the feedback sets corresponding to the 1-bitfirst DCI is 1, the number of the feedback sets corresponding to the1-bit second DCI is 1, the number of the feedback sets corresponding tothe 2-bit first DCI is 3 or 2, and the number of the feedback setscorresponding to the 2-bit second DCI is 3 or 2.

By using the UE of this embodiment to perform the aperiodic feedback ofCSI according to the triggering by the eNB, a relatively good tradeoffbetween feedback flexibility and system signaling overhead may beachieved.

Corresponding to the method of Embodiment 5, an embodiment of thepresent invention further provides an eNB. As the principle of the eNBfor solving problems is similar to that of the method in Embodiment 5,the implementation of the method in Embodiment 5 is referred to for theimplementation of the eNB, and the repeated parts shall not be describedany further. FIG. 26 is a schematic diagram of the structure of the eNB.Referring to FIG. 26, the eNB includes:

a transmitting unit 261 configured to transmit to the UE, 2-bit DCI andfeedback sets corresponding to the DCI preconfigured via RRC signaling,so that the UE aperiodically feeds back CSI of corresponding CA and CoMPaccording to the DCI and the feedback sets corresponding to the DCI.

Wherein, the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI.

Wherein, the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit corresponding to each triggered transmitting point oreach piece of configured CSI.

Wherein, the number of the feedback sets corresponding to the 2-bit DCIis 3 or 2.

By using the eNB of this embodiment to trigger the UE to perform theaperiodic feedback of CSI, a relatively good tradeoff between feedbackflexibility and system signaling overhead may be achieved.

Corresponding to the method of Embodiment 6, an embodiment of thepresent invention further provides user equipment (UE). As the principleof the UE for solving problems is similar to that of the method inEmbodiment 6, the implementation of the method in Embodiment 6 isreferred to for the implementation of the UE, and the repeated partsshall not be described any further. FIG. 27 is a schematic diagram ofthe structure of the UE. Referring to FIG. 27, the UE includes:

a receiving unit 271 configured to receive 2-bit DCI and feedback setscorresponding to the DCI preconfigured via RRC signaling transmitted byan eNB; and

a reporting unit 272 configured to feed back aperiodically CSI ofcorresponding CA and CoMP according to the DCI and the feedback setscorresponding to the DCI.

Wherein, the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI.

Wherein, the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit corresponding to each triggered transmitting point oreach piece of configured CSI.

Wherein, the number of the feedback sets corresponding to the 2-bit DCIis 3 or 2.

By using the UE of this embodiment to perform the aperiodic feedback ofCSI according to the triggering by the eNB, a relatively good tradeoffbetween feedback flexibility and system signaling overhead may beachieved.

Corresponding to the method of Embodiment 7, an embodiment of thepresent invention further provides an eNB. As the principle of the eNBfor solving problems is similar to that of the method in Embodiment 7,the implementation of the method in Embodiment 7 is referred to for theimplementation of the eNB, and the repeated parts shall not be describedany further. FIG. 28 is a schematic diagram of the structure of the eNB.Referring to FIG. 28, the eNB includes:

a transmitting unit 281 configured to transmit to the UE, 2-bit DCI andfeedback sets corresponding to the DCI preconfigured via RRC signaling,so that the UE aperiodically feeds back CSI of corresponding CA and CoMPaccording to the DCI and the feedback sets corresponding to the DCI.

Wherein, the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI.

Wherein, the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating configured or activated carriers, and a TPindication bit for indicating a triggered TP corresponding to eachconfigured or activated carrier or a CSI indication bit for indicatingconfigured CSI corresponding to each configured or activated carrier, orthe RRC signaling including a carrier indication bit for indicatingconfigured or activated carriers, and a carrier indication bit forindicating a carrier corresponding to each triggered TP or correspondingto each piece of configured CSI.

Wherein, the number of the feedback sets corresponding to the 2-bit DCIis 3 or 2.

By using the eNB of this embodiment to trigger the UE to perform theaperiodic feedback of CSI, a relatively good tradeoff between feedbackflexibility and system signaling overhead may be achieved.

Corresponding to the method of Embodiment 8, an embodiment of thepresent invention further provides user equipment (UE). As the principleof the UE for solving problems is similar to that of the method inEmbodiment 8, the implementation of the method in Embodiment 8 isreferred to for the implementation of the UE, and the repeated partsshall not be described any further. FIG. 29 is a schematic diagram ofthe structure of the UE. Referring to FIG. 29, the UE includes:

a receiving unit 291 configured to receive 2-bit DCI and feedback setscorresponding to the DCI preconfigured via RRC signaling transmitted byan eNB; and

a reporting unit 292 configured to feed back aperiodically CSI ofcorresponding CA and CoMP according to the DCI and the feedback setscorresponding to the DCI.

Wherein, the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI.

Wherein, the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating configured or activated carriers, and a TPindication bit for indicating a triggered TP corresponding to eachconfigured or activated carrier or a CSI indication bit for indicatingconfigured CSI corresponding to each configured or activated carrier, orthe RRC signaling including a carrier indication bit for indicatingconfigured or activated carriers, and a carrier indication bit forindicating a carrier corresponding to each triggered TP or configuredCSI.

Wherein, the number of the feedback sets corresponding to the 2-bit DCIis 3 or 2.

By using the UE of this embodiment to perform the aperiodic feedback ofCSI according to the triggering by the eNB, a relatively good tradeoffbetween feedback flexibility and system signaling overhead may beachieved.

Corresponding to the method of Embodiment 9, an embodiment of thepresent invention further provides an eNB. As the principle of the eNBfor solving problems is similar to that of the method in Embodiment 9,the implementation of the method in Embodiment 9 is referred to for theimplementation of the eNB, and the repeated parts shall not be describedany further. FIG. 30 is a schematic diagram of the structure of the eNB.Referring to FIG. 30, the eNB includes:

a transmitting unit 3001 configured to transmit to the UE, 2-bit DCI andfeedback sets corresponding to the DCI preconfigured via RRC signaling,so that the UE aperiodically feeds back CSI of corresponding CA and CoMPaccording to the DCI and the feedback sets corresponding to the DCI.

Wherein, the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI.

Wherein, the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating triggered aperiodically fed back carriers,and a TP indication bit for indicating a triggered TP corresponding toeach triggered carrier or a CSI indication bit for indicating configuredCSI corresponding to each triggered carrier, or the RRC signalingincluding a carrier indication bit for indicating triggeredaperiodically fed back carriers, and a carrier indication bit forindicating a carrier corresponding to each triggered TP or correspondingto each piece of configured CSI.

Wherein, the number of the feedback sets corresponding to the 2-bit DCIis 3 or 2.

By using the eNB of this embodiment to trigger the UE to perform theaperiodic feedback of CSI, a relatively good tradeoff between feedbackflexibility and system signaling overhead may be achieved.

Corresponding to the method of Embodiment 10, an embodiment of thepresent invention further provides user equipment (UE). As the principleof the UE for solving problems is similar to that of the method inEmbodiment 10, the implementation of the method in Embodiment 10 isreferred to for the implementation of the UE, and the repeated partsshall not be described any further. FIG. 31 is a schematic diagram ofthe structure of the UE. Referring to FIG. 31, the UE includes:

a receiving unit 311 configured to receive 2-bit DCI and feedback setscorresponding to the DCI preconfigured via RRC signaling transmitted byan eNB; and

a reporting unit 312 configured to feed back aperiodically CSI ofcorresponding CA and CoMP according to the DCI and the feedback setscorresponding to the DCI.

Wherein, the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI.

Wherein, the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating triggered aperiodically fed back carriers,and a TP indication bit for indicating a triggered TP corresponding to atriggered carrier or a CSI indication bit for indicating configured CSIcorresponding to a triggered carrier, or the RRC signaling including acarrier indication bit for indicating triggered aperiodically fed backcarriers, and a carrier indication bit for indicating a carriercorresponding to each triggered TP or configured CSI.

Wherein, the number of the feedback sets corresponding to the 2-bit DCIis 3 or 2.

By using the UE of this embodiment to perform the aperiodic feedback ofCSI according to the triggering by the eNB, a relatively good tradeoffbetween feedback flexibility and system signaling overhead may beachieved.

Corresponding to the method of Embodiment 11, an embodiment of thepresent invention further provides an eNB. As the principle of the eNBfor solving problems is similar to that of the method in Embodiment 11,the implementation of the method in Embodiment 11 is referred to for theimplementation of the eNB, and the repeated parts shall not be describedany further. FIG. 32 is a schematic diagram of the structure of the eNB.Referring to FIG. 32, the eNB includes:

a transmitting unit 321 configured to transmit to the UE, 2-bit DCI andfeedback sets corresponding to the DCI preconfigured via RRC signaling,so that the UE aperiodically feeds back CSI of corresponding CA and CoMPaccording to the DCI and the feedback sets corresponding to the DCI.

Wherein, the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI.

Wherein, the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating triggered carriers, and a TP indicationbit or a CSI indication bit for indicating fed back contentscorresponding to all triggered carriers.

Wherein, the number of the feedback sets corresponding to the 2-bit DCIis 3 or 2.

By using the eNB of this embodiment to trigger the UE to perform theaperiodic feedback of CSI, a relatively good tradeoff between feedbackflexibility and system signaling overhead may be achieved.

Corresponding to the method of Embodiment 12, an embodiment of thepresent invention further provides user equipment (UE). As the principleof the UE for solving problems is similar to that of the method inEmbodiment 12, the implementation of the method in Embodiment 12 isreferred to for the implementation of the UE, and the repeated partsshall not be described any further. FIG. 33 is a schematic diagram ofthe structure of the UE. Referring to FIG. 33, the UE includes:

a receiving unit 331 configured to receive 2-bit DCI and feedback setscorresponding to the DCI preconfigured via RRC signaling transmitted byan eNB; and

a reporting unit 332 configured to feed back aperiodically CSI ofcorresponding CA and CoMP according to the DCI and the feedback setscorresponding to the DCI.

Wherein, the preconfigured feedback sets corresponding to the DCI areclassified according to a triggered transmitting point or a CSI-RS ofnon-zero power, or are classified according to configured CSI.

Wherein, the preconfigured feedback sets corresponding to the DCI areindicated via RRC signaling, the RRC signaling including a carrierindication bit for indicating triggered carriers, and a TP indicationbit or a CSI indication bit for indicating fed back contentscorresponding to all triggered carriers.

Wherein, the number of the feedback sets corresponding to the 2-bit DCIis 3 or 2.

By using the UE of this embodiment to perform the aperiodic feedback ofCSI according to the triggering by the eNB, a relatively good tradeoffbetween feedback flexibility and system signaling overhead may beachieved.

Corresponding to the method of Embodiment 13, an embodiment of thepresent invention further provides an eNB. As the principle of the eNBfor solving problems is similar to that of the method in Embodiment 13,the implementation of the method in Embodiment 13 is referred to for theimplementation of the eNB, and the repeated parts shall not be describedany further. FIG. 34 is a schematic diagram of the structure of the eNB.Referring to FIG. 34, the eNB includes:

a transmitting unit 341 configured to transmit 1-bit DCI to the UE, sothat the UE aperiodically feeds back corresponding CSI according to theDCI and preconfigured feedback committed information corresponding tothe DCI.

Wherein, the preconfigured feedback committed information correspondingto the DCI is feeding back all the CSI of a first CSI-RS resource ofnon-zero power, or feeding back first CSI in an aperiodic feedback CSIset, or feeding back first CSI in a triggered aperiodic feedback CSIset.

By using the eNB of this embodiment to trigger the UE to perform theaperiodic feedback of CSI, a relatively good tradeoff between feedbackflexibility and system signaling overhead may be achieved.

Corresponding to the method of Embodiment 14, an embodiment of thepresent invention further provides user equipment (UE). As the principleof the UE for solving problems is similar to that of the method inEmbodiment 14, the implementation of the method in Embodiment 14 isreferred to for the implementation of the UE, and the repeated partsshall not be described any further. FIG. 35 is a schematic diagram ofthe structure of the UE. Referring to FIG. 35, the UE includes:

a receiving unit 351 configured to receive 1-bit DCI transmitted by aneNB; and

a reporting unit 352 configured to feed back aperiodically correspondingCSI according to the DCI and preconfigured feedback committedinformation corresponding to the DCI.

Wherein, the preconfigured feedback committed information correspondingto the DCI is feeding back all the CSI of a first CSI-RS resource ofnon-zero power, or feeding back first CSI in an aperiodic feedback CSIset, or feeding back first CSI in a triggered aperiodic feedback CSIset.

By using the UE of this embodiment to perform the aperiodic feedback ofCSI according to the triggering by the eNB, a relatively good tradeoffbetween feedback flexibility and system signaling overhead may beachieved.

Corresponding to the method of Embodiment 15, an embodiment of thepresent invention further provides an eNB. As the principle of the eNBfor solving problems is similar to that of the method in Embodiment 15,the implementation of the method in Embodiment 15 is referred to for theimplementation of the eNB, and the repeated parts shall not be describedany further. FIG. 36 is a schematic diagram of the structure of the eNB.Referring to FIG. 36, the eNB includes:

a transmitting unit 361 configured to transmit to the UE, 1-bit DCI andan anchor CSI resource preconfigured via RRC signaling, so that the UEaperiodically feeds back corresponding CSI according to the DCI and theanchor CSI.

Wherein, the preconfigured anchor CSI resource is at least one CSIresource to which a CSI-RS of non-zero power corresponds, or at leastone CSI resource in an aperiodic feedback CSI set.

Wherein, the preconfigured anchor CSI resource is indicated via RRCsignaling, the RRC signaling including log₂(N) bits, N bits, log₂(M)bits, or M bits, for indicating the anchor CSI resource; where N is thesize of a CoMP measurement set, and M is the size of a CSI setconfigured by the eNB for aperiodic feedback; wherein when the RRCsignaling indicates the anchor CSI resource via N bits or M bits, theindication is performed in a manner of a bitmap.

By using the eNB of this embodiment to trigger the UE to perform theaperiodic feedback of CSI, a relatively good tradeoff between feedbackflexibility and system signaling overhead may be achieved.

Corresponding to the method of Embodiment 16, an embodiment of thepresent invention further provides user equipment (UE). As the principleof the UE for solving problems is similar to that of the method inEmbodiment 16, the implementation of the method in Embodiment 16 isreferred to for the implementation of the UE, and the repeated partsshall not be described any further. FIG. 37 is a schematic diagram ofthe structure of the UE. Referring to FIG. 37, the UE includes:

a receiving unit 371 configured to receive 1-bit DCI and an anchor CSIresource preconfigured via high-layer signaling transmitted by an eNB;and

a reporting unit 372 configured to feed back aperiodically correspondingCSI according to the DCI and the anchor CSI resource.

Wherein, the preconfigured anchor CSI resource is at least one CSIresource to which a CSI-RS of non-zero power corresponds, or at leastone CSI resource in an aperiodic feedback CSI set.

Wherein, the preconfigured anchor CSI resource is indicated via RRCsignaling, the RRC signaling including log₂(N) bits, N bits, log₂(M)bits, or M bits, for indicating the anchor CSI resource; where N is thesize of a CoMP measurement set, and M is the size of a CSI setconfigured by the eNB for aperiodic feedback; wherein when the RRCsignaling indicates the anchor CSI resource via N bits or M bits, theindication is performed in a manner of a bitmap.

By using the UE of this embodiment to perform the aperiodic feedback ofCSI according to the triggering by the eNB, a relatively good tradeoffbetween feedback flexibility and system signaling overhead may beachieved.

An embodiment of the present invention further provides acomputer-readable program, wherein when the program is executed in aneNB, the program enables a computer to carry out the method fortriggering aperiodic feedback in coordinated multipoint transmission asdescribed in embodiments 1, 3, 5, 7, 9, 11, 13 and 15, in the eNB.

An embodiment of the present invention further provides a storage mediumin which a computer-readable program is stored, wherein thecomputer-readable program enables a computer to carry out the method fortriggering aperiodic feedback in coordinated multipoint transmission asdescribed in embodiments 1, 3, 5, 7, 9, 11, 13 and 15, in an eNB.

An embodiment of the present invention further provides acomputer-readable program, wherein when the program is executed interminal equipment, the program enables a computer to carry out themethod for triggering aperiodic feedback in coordinated multipointtransmission as described in embodiments 2, 4, 6, 8, 10, 12, 14 and 16,in the terminal equipment.

An embodiment of the present invention further provides a storage mediumin which a computer-readable program is stored, wherein thecomputer-readable program enables a computer to carry out the method fortriggering aperiodic feedback in coordinated multipoint transmission asdescribed in embodiments 2, 4, 6, 8, 10, 12, 14 and 16, in terminalequipment.

The above apparatuses and methods of the present invention may beimplemented by hardware, or by hardware in combination with software.The present invention relates to such a computer-readable program thatwhen the program is executed by a logic device, the logic device isenabled to carry out the apparatus or components as described above, orto carry out the methods or steps as described above. The presentinvention also relates to a storage medium for storing the aboveprogram, such as a hard disk, a floppy disk, a CD, a DVD, and a flashmemory, etc.

The present invention is described above with reference to particularembodiments. However, it should be understood by those skilled in theart that such a description is illustrative only, and not intended tolimit the protection scope of the present invention. Various variantsand modifications may be made by those skilled in the art according tothe spirits and principle of the present invention, and such variantsand modifications fall within the scope of the present invention.

What is claimed is:
 1. An eNB, configured to trigger a User Equipment(UE) to aperiodically feed back Channel State Indication (CSI), the eNBcomprising: a transmitter configured to transmit to the UE which isconfigured in Coordinated Multipoint Transmission (CoMP) mode, downlinkcontrol information and feedback sets corresponding to the downlinkcontrol information preconfigured via Radio Resource Control (RRC)signaling, so that the UE aperiodically feeds back corresponding CSIaccording to the downlink control information and the feedback setscorresponding to the downlink control information; wherein the feedbacksets corresponding to the downlink control information preconfigured viaRRC signaling are classified according to configured CSI, wherein 1 bitinformation or 2 bit information is used in a CSI request field in thedownlink control information for uplink transmission; when the CSIrequest field is 1 bit information, the feedback sets is one feedbackset corresponding to a value of the CSI request field 1; and when theCSI request field is 2 bit information, the feedback sets are threefeedback sets corresponding respectively to values of the CSI requestfield01, 10 and 11, or the feedback sets are two feedback setscorresponding respectively to the values of the CSI request field 10 and11.
 2. The eNB according to claim 1, wherein each of the feedback setsis configured to indicate a CSI set needing to be triggered, wherein thefeedback sets are indicated via a bitmap of M bits of RRC signaling,where, M is a size of a CSI set configured by the eNB for aperiodicfeedback.
 3. A User Equipment (UE), comprising: a receiver configured toreceive downlink control information and feedback sets corresponding tothe downlink control information preconfigured via Radio ResourceControl (RRC) signaling transmitted by an eNB; and a transmitterconfigured to feed back aperiodically corresponding Channel StateIndication (CSI) according to the downlink control information and thefeedback sets corresponding to the downlink control information; whereinthe feedback sets corresponding to the downlink control informationpreconfigured via RRC signaling are classified according to configuredCSI wherein 1 bit information or 2 bit information is used in a CSIrequest field in the downlink control information for uplinktransmission; when the CSI request field is 1 bit information, thefeedback sets is one feedback set corresponding to a value of the CSIrequest field 1; and when the CSI request field is 2 bit information,the feedback sets are three feedback sets corresponding respectively tovalues of the CSI request field 01, 10 and 11, or the feedback sets aretwo feedback sets corresponding respectively to the values of the CSIrequest field 10 and
 11. 4. The UE according to claim 3, wherein each ofthe feedback sets is configured to indicate a CSI set needing to betriggered, wherein the feedback sets are indicated via a bitmap of Mbits of RRC signaling, where, M is a size of a CSI set configured by theeNB for aperiodic feedback.
 5. An eNB, configured to trigger a UserEquipment (UE) to aperiodically feed back Channel State Indication(CSI), the eNB comprising: a transmitter configured to transmit to theUE, downlink control information and feedback sets corresponding to thedownlink control information configured via Radio Resource Control (RRC)signaling, so that the UE aperiodically feeds back CSI of correspondingCarrier Aggregation (CA) and Coordinated Multipoint Transmission (CoMP)according to the downlink control information and the feedback setscorresponding to the downlink control information; wherein the feedbacksets corresponding to the downlink control information configured viaRRC signaling are classified according to configured CSI, wherein the 1bit information or 2 bit information is used in a CSI request field inthe downlink control information for uplink transmission; when the CSIrequest field is 1 bit information, the feedback sets is one feedbackset corresponding to a value of the CSI request field 1; and when theCSI request field is 2 bit information, the feedback sets are threefeedback sets corresponding respectively to values of the CSI requestfield 01, 10 and 11, or the feedback sets are two feedback setscorresponding respectively to the values of the CSI request field 10 and11.
 6. The eNB according to claim 5, wherein each of the feedback setsis configured to indicate a CSI set needing to be triggered, wherein thefeedback sets are indicated via a bitmap of M bits of RRC signaling,where, M is a size of a CSI set configured by the eNB for aperiodicfeedback.
 7. The eNB according to claim 5, wherein the configuredfeedback sets corresponding to the downlink control information areindicated via RRC signaling, the RRC signaling comprising a carrierindication bit corresponding to each piece of configured CSI.
 8. The eNBaccording to claim 5, wherein the configured feedback sets correspondingto the downlink control information are indicated via RRC signaling, theRRC signaling comprising a carrier indication bit for indicatingconfigured carriers, and a CSI indication bit for indicating configuredCSI corresponding to each configured carrier.
 9. A User Equipment (UE),comprising: a receiver configured to receive downlink controlinformation and feedback sets corresponding to the downlink controlinformation configured via Radio Resource Control (RRC) signalingtransmitted by an eNB; and a transmitter configured to feed backaperiodically Channel State Indication (CSI) of corresponding CarrierAggregation (CA) and Coordinated Multipoint Transmission (CoMP)according to the downlink control information and the feedback setscorresponding to the DCI; wherein the configured feedback setscorresponding to the DCI are classified according to configured CSI,wherein 1 bit information or 2 bit information is used in a CSI requestfield in the downlink control information for uplink transmission; whenthe CSI request field is 1 bit information, the feedback sets is onefeedback set corresponding to a value of CSI request field 1; and whenthe CSI request field is 2 bit information, the feedback sets are threefeedback sets corresponding respectively to values of CSI request field01, 10 and 11, or the feedback sets are two feedback sets correspondingrespectively to the values of CSI request field 10 and
 11. 10. The UEaccording to claim 9, wherein the receiver is configured to receive2-bit DCI; wherein the RRC signaling comprising a carrier indication bitcorresponding to each piece of configured CSI; and wherein the number ofthe feedback sets corresponding to the 2-bit CSI request field is 3 or2.
 11. The UE according to claim 9, wherein the receiver is configuredto receive 2-bit CSI request field; and wherein the configured feedbacksets corresponding to the downlink control information are indicated viaRRC signaling, the RRC signaling comprising a carrier indication bit forindicating configured carriers, and a CSI indication bit for indicatingconfigured CSI corresponding to each configured carrier; and wherein thenumber of the feedback sets corresponding to the 2-bit CSI request fieldis 3 or
 2. 12. The UE according to claim 9, wherein each of the feedbacksets is configured to indicate a CSI set needing to be triggered,wherein the feedback sets are indicated via a bitmap of M bits of RRCsignaling, where, M is a size of a CSI set configured by the eNB foraperiodic feedback.